summaryrefslogtreecommitdiff
path: root/mako/compat.py
blob: 06bb8d99f588c66bb2172b1f24fc7116eb7da135 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
# mako/compat.py
# Copyright 2006-2020 the Mako authors and contributors <see AUTHORS file>
#
# This module is part of Mako and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

import collections
import inspect
import sys

py3k = sys.version_info >= (3, 0)
py2k = sys.version_info < (3,)
py27 = sys.version_info >= (2, 7)
jython = sys.platform.startswith("java")
win32 = sys.platform.startswith("win")
pypy = hasattr(sys, "pypy_version_info")

ArgSpec = collections.namedtuple(
    "ArgSpec", ["args", "varargs", "keywords", "defaults"]
)


def inspect_getargspec(func):
    """getargspec based on fully vendored getfullargspec from Python 3.3."""

    if inspect.ismethod(func):
        func = func.__func__
    if not inspect.isfunction(func):
        raise TypeError("{!r} is not a Python function".format(func))

    co = func.__code__
    if not inspect.iscode(co):
        raise TypeError("{!r} is not a code object".format(co))

    nargs = co.co_argcount
    names = co.co_varnames
    nkwargs = co.co_kwonlyargcount if py3k else 0
    args = list(names[:nargs])

    nargs += nkwargs
    varargs = None
    if co.co_flags & inspect.CO_VARARGS:
        varargs = co.co_varnames[nargs]
        nargs = nargs + 1
    varkw = None
    if co.co_flags & inspect.CO_VARKEYWORDS:
        varkw = co.co_varnames[nargs]

    return ArgSpec(args, varargs, varkw, func.__defaults__)


if py3k:
    from io import StringIO
    import builtins as compat_builtins
    from urllib.parse import quote_plus, unquote_plus
    from html.entities import codepoint2name, name2codepoint

    string_types = (str,)
    binary_type = bytes
    text_type = str

    from io import BytesIO as byte_buffer

    def u(s):
        return s

    def b(s):
        return s.encode("latin-1")

    def octal(lit):
        return eval("0o" + lit)


else:
    import __builtin__ as compat_builtins  # noqa

    try:
        from cStringIO import StringIO
    except:
        from StringIO import StringIO

    byte_buffer = StringIO

    from urllib import quote_plus, unquote_plus  # noqa
    from htmlentitydefs import codepoint2name, name2codepoint  # noqa

    string_types = (basestring,)  # noqa
    binary_type = str
    text_type = unicode  # noqa

    def u(s):
        return unicode(s, "utf-8")  # noqa

    def b(s):
        return s

    def octal(lit):
        return eval("0" + lit)


if py3k:
    from importlib import machinery, util

    if hasattr(util, 'module_from_spec'):
        # Python 3.5+
        def load_module(module_id, path):
            spec = util.spec_from_file_location(module_id, path)
            module = util.module_from_spec(spec)
            spec.loader.exec_module(module)
            return module
    else:
        def load_module(module_id, path):
            module = machinery.SourceFileLoader(module_id, path).load_module()
            del sys.modules[module_id]
            return module

else:
    import imp

    def load_module(module_id, path):
        fp = open(path, "rb")
        try:
            module = imp.load_source(module_id, path, fp)
            del sys.modules[module_id]
            return module
        finally:
            fp.close()


if py3k:

    def reraise(tp, value, tb=None, cause=None):
        if cause is not None:
            value.__cause__ = cause
        if value.__traceback__ is not tb:
            raise value.with_traceback(tb)
        raise value


else:
    exec(
        "def reraise(tp, value, tb=None, cause=None):\n"
        "    raise tp, value, tb\n"
    )


def exception_as():
    return sys.exc_info()[1]


all = all  # noqa


def exception_name(exc):
    return exc.__class__.__name__


################################################
# cross-compatible metaclass implementation
# Copyright (c) 2010-2012 Benjamin Peterson
def with_metaclass(meta, base=object):
    """Create a base class with a metaclass."""
    return meta("%sBase" % meta.__name__, (base,), {})


################################################


def arg_stringname(func_arg):
    """Gets the string name of a kwarg or vararg
    In Python3.4 a function's args are
    of _ast.arg type not _ast.name
    """
    if hasattr(func_arg, "arg"):
        return func_arg.arg
    else:
        return str(func_arg)