django.utils.encoding 源代码
import codecs
import datetime
import locale
from decimal import Decimal
from urllib.parse import quote
from django.utils.functional import Promise
class DjangoUnicodeDecodeError(UnicodeDecodeError):
def __init__(self, obj, *args):
self.obj = obj
super().__init__(*args)
def __str__(self):
return "%s. You passed in %r (%s)" % (
super().__str__(),
self.obj,
type(self.obj),
)
[文档]def smart_str(s, encoding="utf-8", strings_only=False, errors="strict"):
"""
Return a string representing 's'. Treat 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_str(s, encoding, strings_only, errors)
_PROTECTED_TYPES = (
type(None),
int,
float,
Decimal,
datetime.datetime,
datetime.date,
datetime.time,
)
[文档]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_str(strings_only=True).
"""
return isinstance(obj, _PROTECTED_TYPES)
[文档]def force_str(s, encoding="utf-8", strings_only=False, errors="strict"):
"""
Similar to smart_str(), 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), str):
return s
if strings_only and is_protected_type(s):
return s
try:
if isinstance(s, bytes):
s = str(s, encoding, errors)
else:
s = str(s)
except UnicodeDecodeError as e:
raise DjangoUnicodeDecodeError(s, *e.args)
return s
[文档]def smart_bytes(s, encoding="utf-8", strings_only=False, errors="strict"):
"""
Return 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)
[文档]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, memoryview):
return bytes(s)
return str(s).encode(encoding, errors)
[文档]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 RFC 3987 Section 3.1, slightly simplified since
the input is assumed to be a string rather than an arbitrary byte stream.
Take an IRI (string or UTF-8 bytes, e.g. '/I ♥ Django/' or
b'/I \xe2\x99\xa5 Django/') and return a string containing the encoded
result with ASCII chars only (e.g. '/I%20%E2%99%A5%20Django/').
"""
# The list of safe characters here is constructed from the "reserved" and
# "unreserved" characters specified in RFC 3986 Sections 2.2 and 2.3:
# reserved = gen-delims / sub-delims
# gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@"
# sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
# / "*" / "+" / "," / ";" / "="
# unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
# Of the unreserved characters, urllib.parse.quote() already considers all
# but the ~ safe.
# The % character is also added to the list of safe characters here, as the
# end of RFC 3987 Section 3.1 specifically mentions that % must not be
# converted.
if iri is None:
return iri
elif isinstance(iri, Promise):
iri = str(iri)
return quote(iri, safe="/#%[]=:;$&()+,!?*@'~")
# List of byte values that uri_to_iri() decodes from percent encoding.
# First, the unreserved characters from RFC 3986:
_ascii_ranges = [[45, 46, 95, 126], range(65, 91), range(97, 123)]
_hextobyte = {
(fmt % char).encode(): bytes((char,))
for ascii_range in _ascii_ranges
for char in ascii_range
for fmt in ["%02x", "%02X"]
}
# And then everything above 128, because bytes ≥ 128 are part of multibyte
# Unicode characters.
_hexdig = "0123456789ABCDEFabcdef"
_hextobyte.update(
{(a + b).encode(): bytes.fromhex(a + b) for a in _hexdig[8:] for b in _hexdig}
)
[文档]def uri_to_iri(uri):
"""
Convert a Uniform Resource Identifier(URI) into an Internationalized
Resource Identifier(IRI).
This is the algorithm from RFC 3987 Section 3.2, excluding step 4.
Take an URI in ASCII bytes (e.g. '/I%20%E2%99%A5%20Django/') and return
a string containing the encoded result (e.g. '/I%20♥%20Django/').
"""
if uri is None:
return uri
uri = force_bytes(uri)
# Fast selective unquote: First, split on '%' and then starting with the
# second block, decode the first 2 bytes if they represent a hex code to
# decode. The rest of the block is the part after '%AB', not containing
# any '%'. Add that to the output without further processing.
bits = uri.split(b"%")
if len(bits) == 1:
iri = uri
else:
parts = [bits[0]]
append = parts.append
hextobyte = _hextobyte
for item in bits[1:]:
hex = item[:2]
if hex in hextobyte:
append(hextobyte[item[:2]])
append(item[2:])
else:
append(b"%")
append(item)
iri = b"".join(parts)
return repercent_broken_unicode(iri).decode()
[文档]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 RFC
# 3986 Sections 2.2 and 2.3:
# reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","
# unreserved = alphanum | mark
# mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
# The list of safe characters here is constructed subtracting ";", "=",
# and "?" according to RFC 3986 Section 3.3.
# The reason for not subtracting and escaping "/" is that we are escaping
# the entire path, not a path segment.
return quote(path, safe="/:@&+$,-_.!~*'()")
def punycode(domain):
"""Return the Punycode of the given domain if it's non-ASCII."""
return domain.encode("idna").decode("ascii")
def repercent_broken_unicode(path):
"""
As per RFC 3987 Section 3.2, step three of converting a URI into an IRI,
repercent-encode any octet produced that is not part of a strictly legal
UTF-8 octet sequence.
"""
changed_parts = []
while True:
try:
path.decode()
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"/#%[]=:;$&()+,!?*@'~")
changed_parts.append(path[: e.start] + repercent.encode())
path = path[e.end :]
else:
return b"".join(changed_parts) + path
[文档]def filepath_to_uri(path):
"""Convert a file system path to a URI portion that is suitable for
inclusion in a URL.
Encode certain chars that would normally be recognized as special chars
for URIs. Do not encode the ' character, as it is a valid character
within URIs. See the encodeURIComponent() JavaScript function for details.
"""
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(str(path).replace("\\", "/"), safe="/~!*()'")
def get_system_encoding():
"""
The encoding for the character type functions. Fallback to 'ascii' if the
#encoding is unsupported by Python or could not be determined. See tickets
#10335 and #5846.
"""
try:
encoding = locale.getlocale()[1] or "ascii"
codecs.lookup(encoding)
except Exception:
encoding = "ascii"
return encoding
DEFAULT_LOCALE_ENCODING = get_system_encoding()
