Source code for django.utils.encoding

# -*- encoding: utf-8 -*-
from __future__ import unicode_literals

import codecs
import datetime
import locale
from decimal import Decimal

from django.utils import six
from django.utils.functional import Promise
from django.utils.six.moves.urllib.parse import quote, unquote

if six.PY3:
    from urllib.parse import unquote_to_bytes


class DjangoUnicodeDecodeError(UnicodeDecodeError):
    def __init__(self, obj, *args):
        self.obj = obj
        UnicodeDecodeError.__init__(self, *args)

    def __str__(self):
        original = UnicodeDecodeError.__str__(self)
        return '%s. You passed in %r (%s)' % (original, self.obj, type(self.obj))


# For backwards compatibility. (originally in Django, then added to six 1.9)
python_2_unicode_compatible = six.python_2_unicode_compatible


[docs]def smart_text(s, encoding='utf-8', strings_only=False, errors='strict'): """ Returns a text object representing 's' -- unicode on Python 2 and str on Python 3. Treats bytestrings using the 'encoding' codec. If strings_only is True, don't convert (some) non-string-like objects. """ if isinstance(s, Promise): # The input is the result of a gettext_lazy() call. return s return force_text(s, encoding, strings_only, errors)
_PROTECTED_TYPES = six.integer_types + ( type(None), float, Decimal, datetime.datetime, datetime.date, datetime.time )
[docs]def is_protected_type(obj): """Determine if the object instance is of a protected type. Objects of protected types are preserved as-is when passed to force_text(strings_only=True). """ return isinstance(obj, _PROTECTED_TYPES)
[docs]def force_text(s, encoding='utf-8', strings_only=False, errors='strict'): """ Similar to smart_text, except that lazy instances are resolved to strings, rather than kept as lazy objects. If strings_only is True, don't convert (some) non-string-like objects. """ # Handle the common case first for performance reasons. if issubclass(type(s), six.text_type): return s if strings_only and is_protected_type(s): return s try: if not issubclass(type(s), six.string_types): if six.PY3: if isinstance(s, bytes): s = six.text_type(s, encoding, errors) else: s = six.text_type(s) elif hasattr(s, '__unicode__'): s = six.text_type(s) else: s = six.text_type(bytes(s), encoding, errors) else: # Note: We use .decode() here, instead of six.text_type(s, encoding, # errors), so that if s is a SafeBytes, it ends up being a # SafeText at the end. s = s.decode(encoding, errors) except UnicodeDecodeError as e: if not isinstance(s, Exception): raise DjangoUnicodeDecodeError(s, *e.args) else: # If we get to here, the caller has passed in an Exception # subclass populated with non-ASCII bytestring data without a # working unicode method. Try to handle this without raising a # further exception by individually forcing the exception args # to unicode. s = ' '.join(force_text(arg, encoding, strings_only, errors) for arg in s) return s
[docs]def smart_bytes(s, encoding='utf-8', strings_only=False, errors='strict'): """ Returns a bytestring version of 's', encoded as specified in 'encoding'. If strings_only is True, don't convert (some) non-string-like objects. """ if isinstance(s, Promise): # The input is the result of a gettext_lazy() call. return s return force_bytes(s, encoding, strings_only, errors)
[docs]def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'): """ Similar to smart_bytes, except that lazy instances are resolved to strings, rather than kept as lazy objects. If strings_only is True, don't convert (some) non-string-like objects. """ # Handle the common case first for performance reasons. if isinstance(s, bytes): if encoding == 'utf-8': return s else: return s.decode('utf-8', errors).encode(encoding, errors) if strings_only and is_protected_type(s): return s if isinstance(s, six.memoryview): return bytes(s) if isinstance(s, Promise): return six.text_type(s).encode(encoding, errors) if not isinstance(s, six.string_types): try: if six.PY3: return six.text_type(s).encode(encoding) else: return bytes(s) except UnicodeEncodeError: if isinstance(s, Exception): # An Exception subclass containing non-ASCII data that doesn't # know how to print itself properly. We shouldn't raise a # further exception. return b' '.join(force_bytes(arg, encoding, strings_only, errors) for arg in s) return six.text_type(s).encode(encoding, errors) else: return s.encode(encoding, errors)
if six.PY3: smart_str = smart_text force_str = force_text else: smart_str = smart_bytes force_str = force_bytes # backwards compatibility for Python 2 smart_unicode = smart_text force_unicode = force_text smart_str.__doc__ = """ Apply smart_text in Python 3 and smart_bytes in Python 2. This is suitable for writing to sys.stdout (for instance). """ force_str.__doc__ = """ Apply force_text in Python 3 and force_bytes in Python 2. """
[docs]def iri_to_uri(iri): """ Convert an Internationalized Resource Identifier (IRI) portion to a URI portion that is suitable for inclusion in a URL. This is the algorithm from section 3.1 of RFC 3987. However, since we are assuming input is either UTF-8 or unicode already, we can simplify things a little from the full method. Takes an IRI in UTF-8 bytes (e.g. '/I \xe2\x99\xa5 Django/') or unicode (e.g. '/I ♥ Django/') and returns ASCII bytes containing the encoded result (e.g. '/I%20%E2%99%A5%20Django/'). """ # The list of safe characters here is constructed from the "reserved" and # "unreserved" characters specified in sections 2.2 and 2.3 of RFC 3986: # reserved = gen-delims / sub-delims # gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@" # sub-delims = "!" / "$" / "&" / "'" / "(" / ")" # / "*" / "+" / "," / ";" / "=" # unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~" # Of the unreserved characters, urllib.quote already considers all but # the ~ safe. # The % character is also added to the list of safe characters here, as the # end of section 3.1 of RFC 3987 specifically mentions that % must not be # converted. if iri is None: return iri return quote(force_bytes(iri), safe=b"/#%[]=:;$&()+,!?*@'~")
[docs]def uri_to_iri(uri): """ Converts a Uniform Resource Identifier(URI) into an Internationalized Resource Identifier(IRI). This is the algorithm from section 3.2 of RFC 3987. Takes an URI in ASCII bytes (e.g. '/I%20%E2%99%A5%20Django/') and returns unicode containing the encoded result (e.g. '/I \xe2\x99\xa5 Django/'). """ if uri is None: return uri uri = force_bytes(uri) iri = unquote_to_bytes(uri) if six.PY3 else unquote(uri) return repercent_broken_unicode(iri).decode('utf-8')
[docs]def escape_uri_path(path): """ Escape the unsafe characters from the path portion of a Uniform Resource Identifier (URI). """ # These are the "reserved" and "unreserved" characters specified in # sections 2.2 and 2.3 of RFC 2396: # reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | "," # unreserved = alphanum | mark # mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")" # The list of safe characters here is constructed subtracting ";", "=", # and "?" according to section 3.3 of RFC 2396. # The reason for not subtracting and escaping "/" is that we are escaping # the entire path, not a path segment. return quote(force_bytes(path), safe=b"/:@&+$,-_.!~*'()")
def repercent_broken_unicode(path): """ As per section 3.2 of RFC 3987, step three of converting a URI into an IRI, we need to re-percent-encode any octet produced that is not part of a strictly legal UTF-8 octet sequence. """ while True: try: path.decode('utf-8') except UnicodeDecodeError as e: # CVE-2019-14235: A recursion shouldn't be used since the exception # handling uses massive amounts of memory repercent = quote(path[e.start:e.end], safe=b"/#%[]=:;$&()+,!?*@'~") path = path[:e.start] + force_bytes(repercent) + path[e.end:] else: return path
[docs]def filepath_to_uri(path): """Convert a file system path to a URI portion that is suitable for inclusion in a URL. We are assuming input is either UTF-8 or unicode already. This method will encode certain chars that would normally be recognized as special chars for URIs. Note that this method does not encode the ' character, as it is a valid character within URIs. See encodeURIComponent() JavaScript function for more details. Returns an ASCII string containing the encoded result. """ if path is None: return path # I know about `os.sep` and `os.altsep` but I want to leave # some flexibility for hardcoding separators. return quote(force_bytes(path).replace(b"\\", b"/"), safe=b"/~!*()'")
def get_system_encoding(): """ The encoding of the default system locale but falls back to the given fallback encoding if the encoding is unsupported by python or could not be determined. See tickets #10335 and #5846 """ try: encoding = locale.getdefaultlocale()[1] or 'ascii' codecs.lookup(encoding) except Exception: encoding = 'ascii' return encoding DEFAULT_LOCALE_ENCODING = get_system_encoding()
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