twisted.python.compat

module documentation

(source)

Compatibility module to provide backwards compatibility for useful Python features.

This is mainly for use of internal Twisted code. We encourage you to use the latest version of Python directly from your code, if possible.

Function	`bytesEnviron`	Return a `dict` of `os.environ` where all text-strings are encoded into `bytes`.
Function	`cmp`	Compare two objects.
Function	`comparable`	Class decorator that ensures support for the special `__cmp__` method.
Function	`currentframe`	In Python 3, `inspect.currentframe` does not take a stack-level argument. Restore that functionality from Python 2 so we don't have to re-implement the `f_back`-walking loop in places where it's called.
Function	`execfile`	Execute a Python script in the given namespaces.
Function	`intToBytes`	Convert the given integer into `bytes`, as ASCII-encoded Arab numeral.
Function	`ioType`	Determine the type which will be returned from the given file object's read() and accepted by its write() method as an argument.
Function	`items`	Return a list of the items of `d`.
Function	`iterbytes`	Return an iterable wrapper for a `bytes` object that provides the behavior of iterating over `bytes` on Python 2.
Function	`iteritems`	Return an iterable of the items of `d`.
Function	`itervalues`	Return an iterable of the values of `d`.
Function	`lazyByteSlice`	Return a copy of the given bytes-like object.
Function	`nativeString`	Convert `bytes` or `str` to `str` type, using ASCII encoding if conversion is necessary.
Function	`networkString`	Convert a string to `bytes` using ASCII encoding.
Function	`reraise`	Re-raise an exception, with an optional traceback.
Variable	`NativeStringIO`	An in-memory file-like object that operates on the native string type (bytes in Python 2, unicode in Python 3).
Variable	`unicode`	The type of Unicode strings, `unicode` on Python 2 and `str` on Python 3.
Variable	`urllib_parse`	a URL-parsing module (urlparse on Python 2, urllib.parse on Python 3)
Function	`_constructMethod`	Construct a bound method.
Function	`_get_async_param`	Provide a backwards-compatible way to get async param value that does not cause a syntax error under Python 3.7.
Function	`_matchingString`	No summary
Function	`_pypy3BlockingHack`	Work around this pypy bug by replacing `socket.fromfd` with a more conservative version.
Constant	`_PY37PLUS`	Undocumented
Constant	`_PYPY`	Undocumented

def bytesEnviron(): (source)

bytesEnviron was deprecated in Twisted 21.2.0; please use os.environb instead.

Return a dict of os.environ where all text-strings are encoded into bytes.

This function is POSIX only; environment variables are always text strings on Windows.

def cmp(a, b): (source)

Compare two objects.

Returns a negative number if a < b, zero if they are equal, and a positive number if a > b.

def comparable(klass): (source)

Class decorator that ensures support for the special __cmp__ method.

__eq__, __lt__, etc. methods are added to the class, relying on __cmp__ to implement their comparisons.

def currentframe(n=0): (source)

In Python 3, inspect.currentframe does not take a stack-level argument. Restore that functionality from Python 2 so we don't have to re-implement the f_back-walking loop in places where it's called.

Parameters
n:`int`	The number of stack levels above the caller to walk.
Returns
`types.FrameType`	a frame, n levels up the stack from the caller.

def execfile(filename, globals, locals=None): (source)

Execute a Python script in the given namespaces.

Similar to the execfile builtin, but a namespace is mandatory, partly because that's a sensible thing to require, and because otherwise we'd have to do some frame hacking.

This is a compatibility implementation for Python 3 porting, to avoid the use of the deprecated builtin execfile function.

def intToBytes(i): (source)

intToBytes was deprecated in Twisted 21.2.0; please use b'%d' instead.

Convert the given integer into bytes, as ASCII-encoded Arab numeral.

Parameters
i:`int`	The `int` to convert to `bytes`.
Returns
`bytes`	Undocumented

def ioType(fileIshObject, default=str): (source)

Determine the type which will be returned from the given file object's read() and accepted by its write() method as an argument.

In other words, determine whether the given file is 'opened in text mode'.

Parameters
fileIshObject:`object`	Any object, but ideally one which resembles a file.
default:`type`	A default value to return when the type of `fileIshObject` cannot be determined.
Returns
`type`	There are 3 possible return values: `str`, if the file is unambiguously opened in text mode. `bytes`, if the file is unambiguously opened in binary mode. The `default` parameter, if the given type is not understood.

def items(d): (source)

items was deprecated in Twisted 21.2.0; please use list(d.items()) instead.

Return a list of the items of d.

Parameters
d:`dict`	Undocumented
Returns
`list`	Undocumented

def iterbytes(originalBytes): (source)

Return an iterable wrapper for a bytes object that provides the behavior of iterating over bytes on Python 2.

In particular, the results of iteration are the individual bytes (rather than integers as on Python 3).

Parameters
originalBytes	A `bytes` object that will be wrapped.

def iteritems(d): (source)

iteritems was deprecated in Twisted 21.2.0; please use d.items() instead.

Return an iterable of the items of d.

Parameters
d:`dict`	Undocumented
Returns
iterable	Undocumented

def itervalues(d): (source)

itervalues was deprecated in Twisted 21.2.0; please use d.values() instead.

Return an iterable of the values of d.

Parameters
d:`dict`	Undocumented
Returns
iterable	Undocumented

def lazyByteSlice(object, offset=0, size=None): (source)

Return a copy of the given bytes-like object.

If an offset is given, the copy starts at that offset. If a size is given, the copy will only be of that length.

Parameters
object	`bytes` to be copied.
offset	`int`, starting index of copy.
size	Optional, if an `int` is given limit the length of copy to this size.

def nativeString(s): (source)

Convert bytes or str to str type, using ASCII encoding if conversion is necessary.

Parameters
s:`AnyStr`	Undocumented
Returns
`str`	Undocumented
Raises
`UnicodeError`	The input string is not ASCII encodable/decodable.
`TypeError`	The input is neither `bytes` nor `str`.

def networkString(s): (source)

Convert a string to bytes using ASCII encoding.

This is useful for sending text-like bytes that are constructed using string interpolation. For example:

    networkString("Hello %d" % (n,))

Parameters
s:`str`	A string to convert to bytes.
Returns
`bytes`	Undocumented
Raises
`UnicodeError`	The input string is not ASCII encodable.
`TypeError`	The input is not `str`.

def reraise(exception, traceback): (source)

reraise was deprecated in Twisted 21.2.0; please use raise exception.with_traceback(traceback) instead.

Re-raise an exception, with an optional traceback.

Re-raised exceptions will be mutated, with their __traceback__ attribute being set.

Parameters
exception	The exception instance.
traceback	The traceback to use, or `None` indicating a new traceback.

NativeStringIO = (source)

An in-memory file-like object that operates on the native string type (bytes in Python 2, unicode in Python 3).

unicode = (source)

The type of Unicode strings, unicode on Python 2 and str on Python 3.

urllib_parse = (source)

a URL-parsing module (urlparse on Python 2, urllib.parse on Python 3)

def _constructMethod(cls, name, self): (source)

Construct a bound method.

Parameters
cls:`type`	The class that the method should be bound to.
name:native `str`	The name of the method.
self:any object	The object that the method is bound to.
Returns
`types.MethodType`	a bound method

def _get_async_param(isAsync=None, **kwargs): (source)

Provide a backwards-compatible way to get async param value that does not cause a syntax error under Python 3.7.

Parameters
isAsync:`bool`	isAsync param value (should default to None)
**kwargs:`dict`	keyword arguments of the caller (only async is allowed)
Returns
`bool`	Final isAsync param value
Raises
`TypeError`	Both isAsync and async specified.

def _matchingString(constantString, inputString): (source)

Some functions, such as os.path.join, operate on string arguments which may be bytes or text, and wish to return a value of the same type. In those cases you may wish to have a string constant (in the case of os.path.join, that constant would be os.path.sep) involved in the parsing or processing, that must be of a matching type in order to use string operations on it. _matchingString will take a constant string (either bytes or str) and convert it to the same type as the input string. constantString should contain only characters from ASCII; to ensure this, it will be encoded or decoded regardless.

Parameters
constantString:`str` or `bytes`	A string literal used in processing.
inputString:`str` or `bytes`	A byte string or text string provided by the user.
Returns
the type of `inputString`	`constantString` converted into the same type as `inputString`

def _pypy3BlockingHack(): (source)

Work around this pypy bug by replacing socket.fromfd with a more conservative version.

_PY37PLUS: bool = (source)

Undocumented

Value

True

_PYPY: bool = (source)

Undocumented

Value

True