diff options
Diffstat (limited to 'netlib/strutils.py')
-rw-r--r-- | netlib/strutils.py | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/netlib/strutils.py b/netlib/strutils.py deleted file mode 100644 index 57cfbc79..00000000 --- a/netlib/strutils.py +++ /dev/null @@ -1,142 +0,0 @@ -import re -import codecs - - -def always_bytes(unicode_or_bytes, *encode_args): - if isinstance(unicode_or_bytes, str): - return unicode_or_bytes.encode(*encode_args) - elif isinstance(unicode_or_bytes, bytes) or unicode_or_bytes is None: - return unicode_or_bytes - else: - raise TypeError("Expected str or bytes, but got {}.".format(type(unicode_or_bytes).__name__)) - - -def native(s, *encoding_opts): - """ - Convert :py:class:`bytes` or :py:class:`unicode` to the native - :py:class:`str` type, using latin1 encoding if conversion is necessary. - - https://www.python.org/dev/peps/pep-3333/#a-note-on-string-types - """ - if not isinstance(s, (bytes, str)): - raise TypeError("%r is neither bytes nor unicode" % s) - if isinstance(s, bytes): - return s.decode(*encoding_opts) - return s - - -# Translate control characters to "safe" characters. This implementation initially -# replaced them with the matching control pictures (http://unicode.org/charts/PDF/U2400.pdf), -# but that turned out to render badly with monospace fonts. We are back to "." therefore. -_control_char_trans = { - x: ord(".") # x + 0x2400 for unicode control group pictures - for x in range(32) -} -_control_char_trans[127] = ord(".") # 0x2421 -_control_char_trans_newline = _control_char_trans.copy() -for x in ("\r", "\n", "\t"): - del _control_char_trans_newline[ord(x)] - - -_control_char_trans = str.maketrans(_control_char_trans) -_control_char_trans_newline = str.maketrans(_control_char_trans_newline) - - -def escape_control_characters(text: str, keep_spacing=True) -> str: - """ - Replace all unicode C1 control characters from the given text with a single "." - - Args: - keep_spacing: If True, tabs and newlines will not be replaced. - """ - if not isinstance(text, str): - raise ValueError("text type must be unicode but is {}".format(type(text).__name__)) - - trans = _control_char_trans_newline if keep_spacing else _control_char_trans - return text.translate(trans) - - -def bytes_to_escaped_str(data, keep_spacing=False, escape_single_quotes=False): - """ - Take bytes and return a safe string that can be displayed to the user. - - Single quotes are always escaped, double quotes are never escaped: - "'" + bytes_to_escaped_str(...) + "'" - gives a valid Python string. - - Args: - keep_spacing: If True, tabs and newlines will not be escaped. - """ - - if not isinstance(data, bytes): - raise ValueError("data must be bytes, but is {}".format(data.__class__.__name__)) - # We always insert a double-quote here so that we get a single-quoted string back - # https://stackoverflow.com/questions/29019340/why-does-python-use-different-quotes-for-representing-strings-depending-on-their - ret = repr(b'"' + data).lstrip("b")[2:-1] - if not escape_single_quotes: - ret = re.sub(r"(?<!\\)(\\\\)*\\'", lambda m: (m.group(1) or "") + "'", ret) - if keep_spacing: - ret = re.sub( - r"(?<!\\)(\\\\)*\\([nrt])", - lambda m: (m.group(1) or "") + dict(n="\n", r="\r", t="\t")[m.group(2)], - ret - ) - return ret - - -def escaped_str_to_bytes(data): - """ - Take an escaped string and return the unescaped bytes equivalent. - - Raises: - ValueError, if the escape sequence is invalid. - """ - if not isinstance(data, str): - raise ValueError("data must be str, but is {}".format(data.__class__.__name__)) - - # This one is difficult - we use an undocumented Python API here - # as per http://stackoverflow.com/a/23151714/934719 - return codecs.escape_decode(data)[0] - - -def is_mostly_bin(s: bytes) -> bool: - if not s or len(s) == 0: - return False - - return sum( - i < 9 or 13 < i < 32 or 126 < i - for i in s[:100] - ) / len(s[:100]) > 0.3 - - -def is_xml(s: bytes) -> bool: - return s.strip().startswith(b"<") - - -def clean_hanging_newline(t): - """ - Many editors will silently add a newline to the final line of a - document (I'm looking at you, Vim). This function fixes this common - problem at the risk of removing a hanging newline in the rare cases - where the user actually intends it. - """ - if t and t[-1] == "\n": - return t[:-1] - return t - - -def hexdump(s): - """ - Returns: - A generator of (offset, hex, str) tuples - """ - for i in range(0, len(s), 16): - offset = "{:0=10x}".format(i) - part = s[i:i + 16] - x = " ".join("{:0=2x}".format(i) for i in part) - x = x.ljust(47) # 16*2 + 15 - part_repr = native(escape_control_characters( - part.decode("ascii", "replace").replace(u"\ufffd", u"."), - False - )) - yield (offset, x, part_repr) |