[Python-checkins] bpo-32820: Simplify __format__ implementation for ipaddress. (GH-16378)
Serhiy Storchaka
webhook-mailer at python.org
Fri Sep 27 13:03:09 EDT 2019
https://github.com/python/cpython/commit/5d6f5b629394066a5249af25cc01f1a1f0edc138
commit: 5d6f5b629394066a5249af25cc01f1a1f0edc138
branch: master
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2019-09-27T20:02:58+03:00
summary:
bpo-32820: Simplify __format__ implementation for ipaddress. (GH-16378)
Also cache the compiled RE for parsing the format specifier.
files:
M Lib/ipaddress.py
diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index c389f0528823..7d80a52c158a 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -560,6 +560,8 @@ def __reduce__(self):
return self.__class__, (str(self),)
+_address_fmt_re = None
+
@functools.total_ordering
class _BaseAddress(_IPAddressBase):
@@ -623,72 +625,49 @@ def __format__(self, fmt):
Supported presentation types are:
's': returns the IP address as a string (default)
- 'b' or 'n': converts to binary and returns a zero-padded string
+ 'b': converts to binary and returns a zero-padded string
'X' or 'x': converts to upper- or lower-case hex and returns a zero-padded string
+ 'n': the same as 'b' for IPv4 and 'x' for IPv6
For binary and hex presentation types, the alternate form specifier
'#' and the grouping option '_' are supported.
"""
-
# Support string formatting
if not fmt or fmt[-1] == 's':
- # let format() handle it
return format(str(self), fmt)
# From here on down, support for 'bnXx'
+ global _address_fmt_re
+ if _address_fmt_re is None:
+ import re
+ _address_fmt_re = re.compile('(#?)(_?)([xbnX])')
- import re
- fmt_re = '^(?P<alternate>#?)(?P<grouping>_?)(?P<fmt_base>[xbnX]){1}$'
- m = re.match(fmt_re, fmt)
+ m = _address_fmt_re.fullmatch(fmt)
if not m:
return super().__format__(fmt)
- groupdict = m.groupdict()
- alternate = groupdict['alternate']
- grouping = groupdict['grouping']
- fmt_base = groupdict['fmt_base']
+ alternate, grouping, fmt_base = m.groups()
# Set some defaults
if fmt_base == 'n':
if self._version == 4:
fmt_base = 'b' # Binary is default for ipv4
- if self._version == 6:
+ else:
fmt_base = 'x' # Hex is default for ipv6
- # Handle binary formatting
if fmt_base == 'b':
- if self._version == 4:
- # resulting string is '0b' + 32 bits
- # plus 7 _ if needed
- padlen = IPV4LENGTH+2 + (7*len(grouping))
- elif self._version == 6:
- # resulting string is '0b' + 128 bits
- # plus 31 _ if needed
- padlen = IPV6LENGTH+2 + (31*len(grouping))
-
- # Handle hex formatting
- elif fmt_base in 'Xx':
- if self._version == 4:
- # resulting string is '0x' + 8 hex digits
- # plus a single _ if needed
- padlen = int(IPV4LENGTH/4)+2 + len(grouping)
- elif self._version == 6:
- # resulting string is '0x' + 32 hex digits
- # plus 7 _ if needed
- padlen = int(IPV6LENGTH/4)+2 + (7*len(grouping))
-
- retstr = f'{int(self):#0{padlen}{grouping}{fmt_base}}'
+ padlen = self._max_prefixlen
+ else:
+ padlen = self._max_prefixlen // 4
- if fmt_base == 'X':
- retstr = retstr.upper()
+ if grouping:
+ padlen += padlen // 4 - 1
- # If alternate is not set, strip the two leftmost
- # characters ('0b')
- if not alternate:
- retstr = retstr[2:]
+ if alternate:
+ padlen += 2 # 0b or 0x
- return retstr
+ return format(int(self), f'{alternate}0{padlen}{grouping}{fmt_base}')
@functools.total_ordering
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