API Reference

codetransformer.transformers

class codetransformer.transformers.asconstants(*builtin_names, **kwargs)[source]

A code transformer that inlines names as constants.

  • Positional arguments are interpreted as names of builtins (e.g. len, print) to freeze as constants in the decorated function’s namespace.
  • Keyword arguments provide additional custom names to freeze as constants.
  • If invoked with no positional or keyword arguments, asconstants inlines all names in builtins.
Parameters:
  • *builtin_names – Names of builtins to freeze as constants.
  • **kwargs – Additional key-value pairs to bind as constants.

Examples

Freezing Builtins:

>>> from codetransformer.transformers import asconstants
>>>
>>> @asconstants('len')
... def with_asconstants(x):
...     return len(x) * 2
...
>>> def without_asconstants(x):
...     return len(x) * 2
...
>>> len = lambda x: 0
>>> with_asconstants([1, 2, 3])
6
>>> without_asconstants([1, 2, 3])
0

Adding Custom Constants:

>>> @asconstants(a=1)
... def f():
...     return a
...
>>> f()
1
>>> a = 5
>>> f()
1
class codetransformer.transformers.interpolated_strings(*, transform_bytes=True, transform_str=False)[source]

A transformer that interpolates local variables into string literals.

Parameters:
  • transform_bytes (bool, optional) – Whether to transform bytes literals to interpolated unicode strings. Default is True.
  • transform_str (bool, optional) – Whether to interpolate values into unicode strings. Default is False.

Example

>>> @interpolated_strings()
... def foo(a, b):
...     c = a + b
...     return b"{a} + {b} = {c}"
...
>>> foo(1, 2)
'1 + 2 = 3'
bytes_instrs

Yield instructions to call TOS.decode(‘utf-8’).format(**locals()).

str_instrs

Yield instructions to call TOS.format(**locals()).

transform_stringlike(const)[source]

Yield instructions to process a str or bytes constant.

types

Tuple containing types transformed by this transformer.

class codetransformer.transformers.overloaded_complexes(xform)

Transformer that applies a callable to each complex constant in the transformed code object.

Parameters:xform (callable) – A callable to be applied to complex literals.

See also

codetransformer.transformers.literals.overloaded_strs

class codetransformer.transformers.overloaded_floats(xform)

Transformer that applies a callable to each float constant in the transformed code object.

Parameters:xform (callable) – A callable to be applied to float literals.

See also

codetransformer.transformers.literals.overloaded_strs

class codetransformer.transformers.overloaded_ints(xform)

Transformer that applies a callable to each int constant in the transformed code object.

Parameters:xform (callable) – A callable to be applied to int literals.

See also

codetransformer.transformers.literals.overloaded_strs

class codetransformer.transformers.overloaded_lists(xform)

A CodeTransformer for overloading BUILD_LIST instructions.

class codetransformer.transformers.overloaded_sets(xform)

A CodeTransformer for overloading BUILD_SET instructions.

class codetransformer.transformers.overloaded_slices(xform)

A CodeTransformer for overloading BUILD_SLICE instructions.

class codetransformer.transformers.overloaded_strs(xform)

A transformer that overloads string literals.

Rewrites all constants of the form:

"some string"

as:

xform("some string")
Parameters:xform (callable) – Function to call on all string literals in the transformer target.

Examples

>>> @overloaded_strs(lambda x: "ayy lmao ")
... def prepend_foo(s):
...     return "foo" + s
...
>>> prepend_foo("bar")
'ayy lmao bar'
class codetransformer.transformers.overloaded_tuples(xform)

A CodeTransformer for overloading BUILD_TUPLE instructions.

class codetransformer.transformers.pattern_matched_exceptions(matcher=<function match>)[source]

Allows usage of arbitrary expressions and matching functions in except blocks.

When an exception is raised in an except block in a function decorated with pattern_matched_exceptions, a matching function will be called with the block’s expression and the three values returned by sys.exc_info(). If the matching function returns True, we enter the corresponding except-block, otherwise we continue to the next block, or re-raise if there are no more blocks to check

Parameters:matcher (function, optional) –

A function accepting an expression and the values of sys.exc_info, returning True if the exception info “matches” the expression.

The default behavior is to emulate standard python when the match expression is a subtype of Exception, and to compare exc.type and exc.args when the match expression is an instance of Exception.

Example

>>> @pattern_matched_exceptions()
... def foo():
...     try:
...         raise ValueError('bar')
...     except ValueError('buzz'):
...         return 'buzz'
...     except ValueError('bar'):
...         return 'bar'
>>> foo()
'bar'
class codetransformer.transformers.precomputed_slices[source]

An optimizing transformer that precomputes and inlines slice literals.

Example

>>> from dis import dis
>>> def first_five(l):
...     return l[:5]
...
>>> dis(first_five)
  2           0 LOAD_FAST                0 (l)
              3 LOAD_CONST               0 (None)
              6 LOAD_CONST               1 (5)
              9 BUILD_SLICE              2
             12 BINARY_SUBSCR
             13 RETURN_VALUE
>>> dis(precomputed_slices()(first_five))
  2           0 LOAD_FAST                0 (l)
              3 LOAD_CONST               0 (slice(None, 5, None))
              6 BINARY_SUBSCR
              7 RETURN_VALUE
codetransformer.transformers.islice_literals[source]

Transformer that turns slice indexing into an islice object.

Examples

>>> from codetransformer.transformers.literals import islice_literals
>>> @islice_literals
... def f():
...     return map(str, (1, 2, 3, 4))[:2]
...
>>> f()
<itertools.islice at ...>
>>> tuple(f())
('1', '2')
codetransformer.transformers.bytearray_literals

A transformer that converts bytes literals to bytearray.

codetransformer.transformers.decimal_literals

A transformer that converts float literals to Decimal.

codetransformer.code

class codetransformer.code.Code(instrs, argnames=(), *, cellvars=(), freevars=(), name='<code>', filename='<code>', firstlineno=1, lnotab=None, flags=None)[source]

A higher abstraction over python’s CodeType.

See Include/code.h for more information.

Parameters:
  • instrs (iterable of Instruction) – A sequence of codetransformer Instruction objects.
  • argnames (iterable of str, optional) – The names of the arguments to the code object.
  • name (str, optional) – The name of this code object.
  • filename (str, optional) – The file that this code object came from.
  • firstlineno (int, optional) – The first line number of the code in this code object.
  • lnotab (dict[Instruction -> int], optional) – The mapping from instruction to the line that it starts.
  • flags (dict[str -> bool], optional) – Any flags to set. This updates the default flag set.
Variables:
argcount

The number of arguments this code object accepts.

This does not include varargs (*args).

argnames

The names of the arguments to this code object.

The format is: [args] [vararg] [kwonlyargs] [varkwarg] where each group is optional.

bytecode_offset(instr)[source]

Returns the offset of instr in the bytecode representation.

Parameters:instr (Instruction) – The instruction the check the index of.
Returns:idx – The index of instr in this code object in the sparse instructions.
Return type:int
cellvars

The names of the variables closed over by inner code objects.

constructs_new_locals

Does this code object construct new locals?

This is True for things like functions where executing the code needs a new locals dict each time; however, something like a module does not normally need new locals.

consts

The constants referenced in this code object.

dis(file=None)[source]

Print self via the stdlib dis module.

Parameters:file (file-like, optional) – A file-like object into which we should print. Defaults to sys.stdout.
filename

The filename of this code object.

firstlineno

The first source line from self.filename that this code object represents.

flags

The flags of this code object represented as a mapping from flag name to boolean status.

Notes

This is a copy of the underlying flags. Mutations will not affect the code object.

freevars

The names of the variables this code object has closed over.

classmethod from_pycode(co)[source]

Create a Code object from a python code object.

Parameters:co (CodeType) – The python code object.
Returns:code – The codetransformer Code object.
Return type:Code
classmethod from_pyfunc(f)[source]

Create a Code object from a python function object.

Parameters:f (function) – The function from which to construct a code object.
Returns:code – A Code object representing f.__code__.
Return type:Code
index(instr)[source]

Returns the index of instr.

Parameters:instr (Instruction) – The instruction the check the index of.
Returns:idx – The index of instr in this code object.
Return type:int
instrs

The instructions in this code object.

is_coroutine

Is this a coroutine defined with async def?

This is 3.5 and greater.

is_generator

Is this a generator?

is_iterable_coroutine

Is this an async generator defined with types.coroutine?

This is 3.5 and greater.

is_nested

Is this a nested code object?

kwonlyargcount

The number of keyword only arguments this code object accepts.

This does not include varkwargs (**kwargs).

lnotab

The mapping of line number to the first instruction on that line.

name

The name of this code object.

names

The names referenced in this code object.

Names come from instructions like LOAD_GLOBAL or STORE_ATTR where the name of the global or attribute is needed at runtime.

py_flags

The flags of this code object represented as a bitmask.

py_lnotab

The encoded lnotab that python uses to compute when lines start.

Note

See Objects/lnotab_notes.txt in the cpython source for more details.

sparse_instrs

The instructions where the index of an instruction is the bytecode offset of that instruction.

None indicates that no instruction is at that offset.

stacksize

The maximum amount of stack space used by this code object.

to_pycode()[source]

Create a python code object from the more abstract codetransfomer.Code object.

Returns:co – The python code object.
Return type:CodeType
varnames

The names of all of the local variables in this code object.

class codetransformer.code.Flag[source]

An enum describing the bitmask of flags that can be set on a code object.

CO_COROUTINE = <Flag.CO_COROUTINE: 128>
CO_FUTURE_ABSOLUTE_IMPORT = <Flag.CO_FUTURE_ABSOLUTE_IMPORT: 16384>
CO_FUTURE_BARRY_AS_BDFL = <Flag.CO_FUTURE_BARRY_AS_BDFL: 262144>
CO_FUTURE_DIVISION = <Flag.CO_FUTURE_DIVISION: 8192>
CO_FUTURE_GENERATOR_STOP = <Flag.CO_FUTURE_GENERATOR_STOP: 524288>
CO_FUTURE_PRINT_FUNCTION = <Flag.CO_FUTURE_PRINT_FUNCTION: 65536>
CO_FUTURE_UNICODE_LITERALS = <Flag.CO_FUTURE_UNICODE_LITERALS: 131072>
CO_FUTURE_WITH_STATEMENT = <Flag.CO_FUTURE_WITH_STATEMENT: 32768>
CO_GENERATOR = <Flag.CO_GENERATOR: 32>
CO_ITERABLE_COROUTINE = <Flag.CO_ITERABLE_COROUTINE: 256>
CO_NESTED = <Flag.CO_NESTED: 16>
CO_NEWLOCALS = <Flag.CO_NEWLOCALS: 2>
CO_NOFREE = <Flag.CO_NOFREE: 64>
CO_OPTIMIZED = <Flag.CO_OPTIMIZED: 1>
CO_VARARGS = <Flag.CO_VARARGS: 4>
CO_VARKEYWORDS = <Flag.CO_VARKEYWORDS: 8>
max = 1040895
classmethod pack(*, CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS, CO_NESTED, CO_GENERATOR, CO_NOFREE, CO_COROUTINE, CO_ITERABLE_COROUTINE, CO_FUTURE_DIVISION, CO_FUTURE_ABSOLUTE_IMPORT, CO_FUTURE_WITH_STATEMENT, CO_FUTURE_PRINT_FUNCTION, CO_FUTURE_UNICODE_LITERALS, CO_FUTURE_BARRY_AS_BDFL, CO_FUTURE_GENERATOR_STOP)[source]

Pack a flags into a bitmask.

I hope you like kwonly args.

Parameters:
  • CO_OPTIMIZED (bool) –
  • CO_NEWLOCALS (bool) –
  • CO_VARARGS (bool) –
  • CO_VARKEYWORDS (bool) –
  • CO_NESTED (bool) –
  • CO_GENERATOR (bool) –
  • CO_NOFREE (bool) –
  • CO_COROUTINE (bool) –
  • CO_ITERABLE_COROUTINE (bool) –
  • CO_FUTURE_DIVISION (bool) –
  • CO_FUTURE_ABSOLUTE_IMPORT (bool) –
  • CO_FUTURE_WITH_STATEMENT (bool) –
  • CO_FUTURE_PRINT_FUNCTION (bool) –
  • CO_FUTURE_UNICODE_LITERALS (bool) –
  • CO_FUTURE_BARRY_AS_BDFL (bool) –
  • CO_FUTURE_GENERATOR_STOP (bool) –
Returns:

mask

Return type:

int

classmethod unpack(mask)[source]

Unpack a bitmask into a map of flag to bool.

Parameters:mask (int) – A bitmask
Returns:mapping – The mapping of flag name to flag status.
Return type:OrderedDict[str -> bool]

codetransformer.core

class codetransformer.core.CodeTransformer[source]

A code object transformer, similar to the NodeTransformer from the ast module.

Variables:code
begin(startcode)[source]

Begin a new startcode.

Parameters:startcode (any) – The startcode to begin.
code

The code object we are currently manipulating.

context

Lookup the current transformation context.

Raises:NoContext – Raised when there is no active transformation context.
startcode

The startcode we are currently in.

transform(code, *, name=None, filename=None)[source]

Transform a codetransformer.Code object applying the transforms.

Parameters:
  • code (Code) – The code object to transform.
  • name (str, optional) – The new name for this code object.
  • filename (str, optional) – The new filename for this code object.
Returns:

new_code – The transformed code object.

Return type:

Code

transform_cellvars(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any
transform_consts(consts)[source]

transformer for the co_consts field.

Override this method to transform the co_consts of the code object.

Parameters:consts (tuple) – The co_consts
Returns:new_consts – The new constants.
Return type:tuple
transform_defaults(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any
transform_freevars(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any
transform_name(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any
transform_names(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any
transform_varnames(obj)

Identity function.

Parameters:obj (any) – The object to return
Returns:obj – The input unchanged
Return type:any

codetransformer.instructions

For details on particular instructions, see the dis stdlib module docs.

class codetransformer.instructions.Instruction(arg=no_default)[source]

Base class for all instruction types.

Parameters:arg (any, optional) – The argument for the instruction. This should be the actual value of the argument, for example, if this is a LOAD_CONST, use the constant value, not the index that would appear in the bytecode.
absjmp
equiv(instr)[source]

Check equivalence of instructions. This checks against the types and the arguments of the instructions

Parameters:instr (Instruction) – The instruction to check against.
Returns:is_equiv – If the instructions are equivalent.
Return type:bool

Notes

This is a separate concept from instruction identity. Two separate instructions can be equivalent without being the same exact instance. This means that two equivalent instructions can be at different points in the bytecode or be targeted by different jumps.

classmethod from_opcode(opcode, arg=no_default)[source]

Create an instruction from an opcode and raw argument.

Parameters:
  • opcode (int) – Opcode for the instruction to create.
  • arg (int, optional) – The argument for the instruction.
Returns:

intsr – An instance of the instruction named by opcode.

Return type:

Instruction

have_arg
opcode
opname
reljmp
stack_effect

The net effect of executing this instruction on the interpreter stack.

Instructions that pop values off the stack have negative stack effect equal to the number of popped values.

Instructions that push values onto the stack have positive stack effect equal to the number of popped values.

Examples

  • LOAD_{FAST,NAME,GLOBAL,DEREF} push one value onto the stack. They have a stack_effect of 1.
  • POP_JUMP_IF_{TRUE,FALSE} always pop one value off the stack. They have a stack effect of -1.
  • BINARY_* instructions pop two instructions off the stack, apply a binary operator, and push the resulting value onto the stack. They have a stack effect of -1 (-2 values consumed + 1 value pushed).
steal(instr)[source]

Steal the jump index off of instr.

This makes anything that would have jumped to instr jump to this Instruction instead.

Parameters:instr (Instruction) – The instruction to steal the jump sources from.
Returns:self – The instruction that owns this method.
Return type:Instruction

Notes

This mutates self and instr inplace.

class codetransformer.instructions.BEFORE_ASYNC_WITH(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 52
opname = 'BEFORE_ASYNC_WITH'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_ADD(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 23
opname = 'BINARY_ADD'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_AND(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 64
opname = 'BINARY_AND'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_FLOOR_DIVIDE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 26
opname = 'BINARY_FLOOR_DIVIDE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_LSHIFT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 62
opname = 'BINARY_LSHIFT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_MATRIX_MULTIPLY(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 16
opname = 'BINARY_MATRIX_MULTIPLY'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_MODULO(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 22
opname = 'BINARY_MODULO'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_MULTIPLY(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 20
opname = 'BINARY_MULTIPLY'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_OR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 66
opname = 'BINARY_OR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_POWER(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 19
opname = 'BINARY_POWER'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_RSHIFT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 63
opname = 'BINARY_RSHIFT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_SUBSCR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 25
opname = 'BINARY_SUBSCR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_SUBTRACT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 24
opname = 'BINARY_SUBTRACT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_TRUE_DIVIDE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 27
opname = 'BINARY_TRUE_DIVIDE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BINARY_XOR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 65
opname = 'BINARY_XOR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BREAK_LOOP(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 80
opname = 'BREAK_LOOP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_LIST(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 103
opname = 'BUILD_LIST'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_LIST_UNPACK(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 149
opname = 'BUILD_LIST_UNPACK'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_MAP(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 105
opname = 'BUILD_MAP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_MAP_UNPACK(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 150
opname = 'BUILD_MAP_UNPACK'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_MAP_UNPACK_WITH_CALL(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 151
opname = 'BUILD_MAP_UNPACK_WITH_CALL'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_SET(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 104
opname = 'BUILD_SET'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_SET_UNPACK(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 153
opname = 'BUILD_SET_UNPACK'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_SLICE(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 133
opname = 'BUILD_SLICE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_TUPLE(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 102
opname = 'BUILD_TUPLE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.BUILD_TUPLE_UNPACK(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 152
opname = 'BUILD_TUPLE_UNPACK'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.CALL_FUNCTION(packed=no_default, *, positional=0, keyword=0)
absjmp = False
have_arg = True
is_jmp = False
opcode = 131
opname = 'CALL_FUNCTION'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.CALL_FUNCTION_KW(packed=no_default, *, positional=0, keyword=0)
absjmp = False
have_arg = True
is_jmp = False
opcode = 141
opname = 'CALL_FUNCTION_KW'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.CALL_FUNCTION_VAR(packed=no_default, *, positional=0, keyword=0)
absjmp = False
have_arg = True
is_jmp = False
opcode = 140
opname = 'CALL_FUNCTION_VAR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.CALL_FUNCTION_VAR_KW(packed=no_default, *, positional=0, keyword=0)
absjmp = False
have_arg = True
is_jmp = False
opcode = 142
opname = 'CALL_FUNCTION_VAR_KW'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.COMPARE_OP(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 107
opname = 'COMPARE_OP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.CONTINUE_LOOP(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 119
opname = 'CONTINUE_LOOP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.DELETE_ATTR(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 96
opname = 'DELETE_ATTR'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.DELETE_DEREF(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 138
opname = 'DELETE_DEREF'
reljmp = False
uses_free = True
uses_name = False
uses_varname = False
vartype
class codetransformer.instructions.DELETE_FAST(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 126
opname = 'DELETE_FAST'
reljmp = False
uses_free = False
uses_name = False
uses_varname = True
class codetransformer.instructions.DELETE_GLOBAL(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 98
opname = 'DELETE_GLOBAL'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.DELETE_NAME(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 91
opname = 'DELETE_NAME'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.DELETE_SUBSCR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 61
opname = 'DELETE_SUBSCR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.DUP_TOP(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 4
opname = 'DUP_TOP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.DUP_TOP_TWO(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 5
opname = 'DUP_TOP_TWO'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.END_FINALLY(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 88
opname = 'END_FINALLY'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.EXTENDED_ARG(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 144
opname = 'EXTENDED_ARG'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.FOR_ITER(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 93
opname = 'FOR_ITER'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.GET_AITER(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 50
opname = 'GET_AITER'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.GET_ANEXT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 51
opname = 'GET_ANEXT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.GET_AWAITABLE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 73
opname = 'GET_AWAITABLE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.GET_ITER(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 68
opname = 'GET_ITER'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.GET_YIELD_FROM_ITER(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 69
opname = 'GET_YIELD_FROM_ITER'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.IMPORT_FROM(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 109
opname = 'IMPORT_FROM'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.IMPORT_NAME(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 108
opname = 'IMPORT_NAME'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.IMPORT_STAR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 84
opname = 'IMPORT_STAR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_ADD(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 55
opname = 'INPLACE_ADD'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_AND(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 77
opname = 'INPLACE_AND'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_FLOOR_DIVIDE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 28
opname = 'INPLACE_FLOOR_DIVIDE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_LSHIFT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 75
opname = 'INPLACE_LSHIFT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_MATRIX_MULTIPLY(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 17
opname = 'INPLACE_MATRIX_MULTIPLY'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_MODULO(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 59
opname = 'INPLACE_MODULO'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_MULTIPLY(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 57
opname = 'INPLACE_MULTIPLY'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_OR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 79
opname = 'INPLACE_OR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_POWER(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 67
opname = 'INPLACE_POWER'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_RSHIFT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 76
opname = 'INPLACE_RSHIFT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_SUBTRACT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 56
opname = 'INPLACE_SUBTRACT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_TRUE_DIVIDE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 29
opname = 'INPLACE_TRUE_DIVIDE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.INPLACE_XOR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 78
opname = 'INPLACE_XOR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.JUMP_ABSOLUTE(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 113
opname = 'JUMP_ABSOLUTE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.JUMP_FORWARD(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 110
opname = 'JUMP_FORWARD'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.JUMP_IF_FALSE_OR_POP(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 111
opname = 'JUMP_IF_FALSE_OR_POP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.JUMP_IF_TRUE_OR_POP(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 112
opname = 'JUMP_IF_TRUE_OR_POP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.LIST_APPEND(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 145
opname = 'LIST_APPEND'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.LOAD_ATTR(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 106
opname = 'LOAD_ATTR'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.LOAD_BUILD_CLASS(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 71
opname = 'LOAD_BUILD_CLASS'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.LOAD_CLASSDEREF(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 148
opname = 'LOAD_CLASSDEREF'
reljmp = False
uses_free = True
uses_name = False
uses_varname = False
vartype
class codetransformer.instructions.LOAD_CLOSURE(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 135
opname = 'LOAD_CLOSURE'
reljmp = False
uses_free = True
uses_name = False
uses_varname = False
vartype
class codetransformer.instructions.LOAD_CONST(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 100
opname = 'LOAD_CONST'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.LOAD_DEREF(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 136
opname = 'LOAD_DEREF'
reljmp = False
uses_free = True
uses_name = False
uses_varname = False
vartype
class codetransformer.instructions.LOAD_FAST(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 124
opname = 'LOAD_FAST'
reljmp = False
uses_free = False
uses_name = False
uses_varname = True
class codetransformer.instructions.LOAD_GLOBAL(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 116
opname = 'LOAD_GLOBAL'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.LOAD_NAME(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 101
opname = 'LOAD_NAME'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.MAKE_CLOSURE(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 134
opname = 'MAKE_CLOSURE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.MAKE_FUNCTION(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 132
opname = 'MAKE_FUNCTION'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.MAP_ADD(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 147
opname = 'MAP_ADD'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.NOP(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 9
opname = 'NOP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.POP_BLOCK(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 87
opname = 'POP_BLOCK'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.POP_EXCEPT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 89
opname = 'POP_EXCEPT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.POP_JUMP_IF_FALSE(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 114
opname = 'POP_JUMP_IF_FALSE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.POP_JUMP_IF_TRUE(arg=no_default)
absjmp = True
have_arg = True
is_jmp = True
opcode = 115
opname = 'POP_JUMP_IF_TRUE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.POP_TOP(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 1
opname = 'POP_TOP'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.PRINT_EXPR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 70
opname = 'PRINT_EXPR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.RAISE_VARARGS(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 130
opname = 'RAISE_VARARGS'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.RETURN_VALUE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 83
opname = 'RETURN_VALUE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.ROT_THREE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 3
opname = 'ROT_THREE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.ROT_TWO(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 2
opname = 'ROT_TWO'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SETUP_ASYNC_WITH(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 154
opname = 'SETUP_ASYNC_WITH'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SETUP_EXCEPT(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 121
opname = 'SETUP_EXCEPT'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SETUP_FINALLY(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 122
opname = 'SETUP_FINALLY'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SETUP_LOOP(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 120
opname = 'SETUP_LOOP'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SETUP_WITH(arg=no_default)
absjmp = False
have_arg = True
is_jmp = True
opcode = 143
opname = 'SETUP_WITH'
reljmp = True
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.SET_ADD(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 146
opname = 'SET_ADD'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.STORE_ATTR(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 95
opname = 'STORE_ATTR'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.STORE_DEREF(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 137
opname = 'STORE_DEREF'
reljmp = False
uses_free = True
uses_name = False
uses_varname = False
vartype
class codetransformer.instructions.STORE_FAST(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 125
opname = 'STORE_FAST'
reljmp = False
uses_free = False
uses_name = False
uses_varname = True
class codetransformer.instructions.STORE_GLOBAL(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 97
opname = 'STORE_GLOBAL'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.STORE_NAME(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 90
opname = 'STORE_NAME'
reljmp = False
uses_free = False
uses_name = True
uses_varname = False
class codetransformer.instructions.STORE_SUBSCR(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 60
opname = 'STORE_SUBSCR'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNARY_INVERT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 15
opname = 'UNARY_INVERT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNARY_NEGATIVE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 11
opname = 'UNARY_NEGATIVE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNARY_NOT(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 12
opname = 'UNARY_NOT'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNARY_POSITIVE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 10
opname = 'UNARY_POSITIVE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNPACK_EX(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 94
opname = 'UNPACK_EX'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.UNPACK_SEQUENCE(arg=no_default)
absjmp = False
have_arg = True
is_jmp = False
opcode = 92
opname = 'UNPACK_SEQUENCE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.WITH_CLEANUP_FINISH(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 82
opname = 'WITH_CLEANUP_FINISH'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.WITH_CLEANUP_START(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 81
opname = 'WITH_CLEANUP_START'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.YIELD_FROM(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 72
opname = 'YIELD_FROM'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False
class codetransformer.instructions.YIELD_VALUE(arg=no_default)
absjmp = False
have_arg = False
is_jmp = False
opcode = 86
opname = 'YIELD_VALUE'
reljmp = False
uses_free = False
uses_name = False
uses_varname = False

codetransformer.patterns

class codetransformer.patterns.pattern(*matchables, startcodes=(0, ))[source]

A pattern of instructions that can be matched against.

This class is intended to be used as a decorator on methods of CodeTransformer subclasses. It is used to mark that a given method should be called on sequences of instructions that match the pattern described by the inputs.

Parameters:
  • *matchables (iterable of matchable) – The type of instructions to match against.
  • startcodes (container of any) – The startcodes where this pattern should be tried.

Examples

Match a single BINARY_ADD instruction:

pattern(BINARY_ADD)

Match a single BINARY_ADD followed by a RETURN_VALUE:

pattern(BINARY_ADD, RETURN_VALUE)

Match a single BINARY_ADD followed by any other single instruction:

pattern(BINARY_ADD, matchany)

Match a single BINARY_ADD followed by any number of instructions:

pattern(BINARY_ADD, matchany[var])
codetransformer.patterns.DEFAULT_STARTCODE = 0

The default startcode for patterns.

DSL Objects

codetransformer.patterns.matchany = ...[source]

Matchable that matches any instruction.

class codetransformer.patterns.seq(*matchables)[source]

A sequence of matchables to match in order.

Parameters:*matchables (iterable of matchable) – The matchables to match against.
codetransformer.patterns.var = *[source]

Modifier that matches zero or more of a pattern.

codetransformer.patterns.plus = +[source]

Modifier that matches one or more of a pattern.

codetransformer.patterns.option = ?[source]

Modifier that matches zero or one of a pattern.

codetransformer.utils

codetransformer.utils.pretty

Utilities for pretty-printing ASTs and code objects.

codetransformer.utils.pretty.a(text, mode='exec', indent=' ', file=None)[source]

Interactive convenience for displaying the AST of a code string.

Writes a pretty-formatted AST-tree to file.

Parameters:
  • text (str) – Text of Python code to render as AST.
  • mode ({'exec', 'eval'}, optional) – Mode for ast.parse. Default is ‘exec’.
  • indent (str, optional) – String to use for indenting nested expressions. Default is two spaces.
  • file (None or file-like object, optional) – File to use to print output. If the default of None is passed, we use sys.stdout.
codetransformer.utils.pretty.d(obj, mode='exec', file=None)[source]

Interactive convenience for displaying the disassembly of a function, module, or code string.

Compiles text and recursively traverses the result looking for code objects to render with dis.dis.

Parameters:
  • obj (str, CodeType, or object with __code__ attribute) – Object to disassemble. If obj is an instance of CodeType, we use it unchanged. If obj is a string, we compile it with mode and then disassemble. Otherwise, we look for a __code__ attribute on obj.
  • mode ({'exec', 'eval'}, optional) – Mode for compile. Default is ‘exec’.
  • file (None or file-like object, optional) – File to use to print output. If the default of None is passed, we use sys.stdout.
codetransformer.utils.pretty.display(text, mode='exec', file=None)[source]

Show text, rendered as AST and as Bytecode.

Parameters:
  • text (str) – Text of Python code to render.
  • mode ({'exec', 'eval'}, optional) – Mode for ast.parse and compile. Default is ‘exec’.
  • file (None or file-like object, optional) – File to use to print output. If the default of None is passed, we use sys.stdout.
codetransformer.utils.pretty.pformat_ast(node, include_attributes=False, indent=' ')[source]

Pretty-format an AST tree element

Parameters:
  • node (ast.AST) – Top-level node to render.
  • include_attributes (bool, optional) – Whether to include node attributes. Default False.
  • indent (str, optional.) – Indentation string for nested expressions. Default is two spaces.
codetransformer.utils.pretty.pprint_ast(node, include_attributes=False, indent=' ', file=None)[source]

Pretty-print an AST tree.

Parameters:
  • node (ast.AST) – Top-level node to render.
  • include_attributes (bool, optional) – Whether to include node attributes. Default False.
  • indent (str, optional.) – Indentation string for nested expressions. Default is two spaces.
  • file (None or file-like object, optional) – File to use to print output. If the default of None is passed, we use sys.stdout.

codetransformer.utils.immutable

Utilities for creating and working with immutable objects.

class codetransformer.utils.immutable.immutable[source]

A base class for immutable objects.

class codetransformer.utils.immutable.lazyval(func)[source]

A memoizing property.

Parameters:func (callable) – The function used to compute the value of the descriptor.
class codetransformer.utils.immutable.immutableattr(attr)[source]

An immutable attribute of a class.

Parameters:attr (any) – The attribute.

codetransformer.utils.functional

Utilities for functional programming.

codetransformer.utils.functional.ffill(iterable)[source]

Forward fill non None values in some iterable.

Parameters:iterable (iterable) – The iterable to forward fill.
Yields:e (any) – The last non None value or None if there has not been a non None value.
codetransformer.utils.functional.flatten(seq, *, recurse_types=(<class 'tuple'>, <class 'list'>, <class 'set'>, <class 'frozenset'>))[source]

Convert a (possibly nested) iterator into a flattened iterator.

Parameters:
  • seq (iterable) – The sequence to flatten.
  • optional (recurse_types,) – Types to recursively flatten. Defaults to (tuple, list, set, frozenset).
  • list(flatten((1, (2, 3), ((4,), 5)))) (>>>) –
  • 2, 3, 4, 5] ([1,) –
  • list(flatten(["abc", "def"], recurse_types=(str,))) (>>>) –
  • 'b', 'c', 'd', 'e', 'f'] (['a',) –
codetransformer.utils.functional.is_a(type_)[source]

More curryable version of isinstance.

codetransformer.utils.functional.not_a(type_)[source]

More curryable version of not isinstance.

codetransformer.utils.functional.reverse_dict(d)[source]

Reverse a dictionary, replacing the keys and values.

Parameters:d (dict) – The dict to reverse.
Returns:rd – The dict with the keys and values flipped.
Return type:dict

Examples

>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> e = reverse_dict(d)
>>> e == {1: 'a', 2: 'b', 3: 'c'}
True
codetransformer.utils.functional.scanl(f, n, ns)[source]

Reduce ns by f starting with n yielding each intermediate value.

tuple(scanl(f, n, ns))[-1] == reduce(f, ns, n)

Parameters:
  • f (callable) – A binary function.
  • n (any) – The starting value.
  • ns (iterable of any) – The iterable to scan over.
Yields:

p (any) – The value of reduce(f, ns[:idx]) where idx is the current index.

Examples

>>> import operator as op
>>> tuple(scanl(op.add, 0, (1, 2, 3, 4)))
(0, 1, 3, 6, 10)

codetransformer.decompiler