twisted.python.compat
module documentationtwisted.python
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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.
Variable | unicode | The type of Unicode strings, unicode on Python 2 and str on Python 3. |
Variable | NativeStringIO | An in-memory file-like object that operates on the native string type (bytes in Python 2, unicode in Python 3). |
Variable | urllib_parse | a URL-parsing module (urlparse on Python 2, urllib.parse on Python 3) |
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 | inet_pton | Emulator of socket.inet_pton . |
Function | inet_ntop | Undocumented |
Function | execfile | Execute a Python script in the given namespaces. |
Function | cmp | Compare two objects. |
Function | comparable | Class decorator that ensures support for the special __cmp__ method. |
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 | nativeString | Convert bytes or unicode to the native str type, using ASCII encoding if conversion is necessary. |
Function | reraise | Undocumented |
Function | iterbytes | Undocumented |
Function | intToBytes | Undocumented |
Function | lazyByteSlice | Return a copy of the given bytes-like object. |
Function | networkString | Undocumented |
Function | iteritems | Undocumented |
Function | itervalues | Undocumented |
Function | items | Undocumented |
Function | bytesEnviron | Return a dict of os.environ where all text-strings are encoded into bytes . |
Variable | __all__ | Undocumented |
Variable | _PY3 | Undocumented |
Variable | _PY35PLUS | Undocumented |
Variable | _PY37PLUS | Undocumented |
Variable | _PYPY | Undocumented |
Function | _shouldEnableNewStyle | No summary |
Variable | _EXPECT_NEWSTYLE | Undocumented |
Function | _matchingString | No summary |
Function | _keys | Return a list of the keys of d . |
Function | _constructMethod | Construct a bound method. |
Function | _bytesChr | Like chr but always works on ASCII, returning bytes . |
Function | _coercedUnicode | Coerce ASCII-only byte strings into unicode for Python 2. |
Function | _bytesRepr | Provide a repr for a byte string that begins with 'b' on both Python 2 and 3. |
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 | _pypy3BlockingHack | Work around this pypy bug by replacing socket.fromfd with a more conservative version. |
Returns whether or not we should enable the new-style conversion of old-style classes. It inspects the environment for TWISTED_NEWSTYLE
, accepting an empty string, no
, false
, False
, and 0
as falsey values and everything else as a truthy value.
Returns | (type: bool ) |
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 | The number of stack levels above the caller to walk. (type: int ) |
Returns | a frame, n levels up the stack from the caller. (type: types.FrameType ) |
Emulator of socket.inet_pton
.
Parameters | af | An address family to parse; socket.AF_INET or socket.AF_INET6 . (type: int ) |
addr | An address. (type: native str ) | |
Returns | The binary packed version of the passed address. (type: bytes ) |
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.
Compare two objects.
Returns a negative number if a < b
, zero if they are equal, and a positive number if a > b
.
Class decorator that ensures support for the special __cmp__
method.
On Python 2 this does nothing.
On Python 3, __eq__
, __lt__
, etc. methods are added to the class, relying on __cmp__
to implement their comparisons.
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 | Any object, but ideally one which resembles a file. (type: object ) |
default | A default value to return when the type of fileIshObject cannot be determined. (type: type ) | |
Returns | There are 3 possible return values:
type ) |
Convert bytes
or unicode
to the native str
type, using ASCII encoding if conversion is necessary.
Raises | UnicodeError | The input string is not ASCII encodable/decodable. |
TypeError | The input is neither bytes nor unicode . |
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 unicode
) 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 | A string literal used in processing. (type: unicode or bytes ) |
inputString | A byte string or text string provided by the user. (type: unicode or bytes ) | |
Returns | constantString converted into the same type as inputString (type: the type of inputString ) |
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. |
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.
Construct a bound method.
Parameters | cls | The class that the method should be bound to. (type: types.ClassType or type .) |
name | The name of the method. (type: native str ) | |
self | The object that the method is bound to. (type: any object) | |
Returns | a bound method (type: types.MethodType ) |
Coerce ASCII-only byte strings into unicode for Python 2.
In Python 2 unicode(b'bytes')
returns a unicode string 'bytes'
. In Python 3, the equivalent str(b'bytes')
will return "b'bytes'"
instead. This function mimics the behavior for Python 2. It will decode the byte string as ASCII. In Python 3 it simply raises a TypeError
when passing a byte string. Unicode strings are returned as-is.
Parameters | s | The string to coerce. (type: bytes or unicode ) |
Raises | UnicodeError | The input bytes is not ASCII decodable. |
TypeError | The input is bytes on Python 3. |
Provide a backwards-compatible way to get async param value that does not cause a syntax error under Python 3.7.
Parameters | isAsync | isAsync param value (should default to None) (type: bool ) |
kwargs | keyword arguments of the caller (only async is allowed) (type: dict ) | |
Returns | Final isAsync param value (type: bool ) | |
Raises | TypeError | Both isAsync and async specified. |
Work around this pypy bug by replacing socket.fromfd
with a more conservative version.