我发现自己要处理很多格式不正确的字符串，这些字符串有双空格、制表符、点前的单空格、尾随空格等等。有什么东西可以美化我可以安装和导入的文本吗？示例：
\t\t\r\t \n \n I find myself
dealing with a lot of poorly formatted
strings that have double spaces, tabs,single spaces
before dots , trailing
spaces and so on. \t Is there something
that prettifies text that I can just install and import ? \t
Example: \t
【问题讨论】：
标签： python-module text-formatting
检查此脚本 Change.py 将其称为：
重新缩进[-d][-r][-v] [路径...]
#! /usr/bin/env python
"""reindent [-d][-r][-v] [ path ... ]
-d (--dryrun) Dry run. Analyze, but don't make any changes to, files.
-r (--recurse) Recurse. Search for all .py files in subdirectories too.
-n (--nobackup) No backup. Does not make a ".bak" file before reindenting.
-v (--verbose) Verbose. Print informative msgs; else no output.
-h (--help) Help. Print this usage information and exit.
Change Python (.py) files to use 4-space indents and no hard tab characters.
Also trim excess spaces and tabs from ends of lines, and remove empty lines
at the end of files. Also ensure the last line ends with a newline.
If no paths are given on the command line, reindent operates as a filter,
reading a single source file from standard input and writing the transformed
source to standard output. In this case, the -d, -r and -v flags are
ignored.
You can pass one or more file and/or directory paths. When a directory
path, all .py files within the directory will be examined, and, if the -r
option is given, likewise recursively for subdirectories.
If output is not to standard output, reindent overwrites files in place,
renaming the originals with a .bak extension. If it finds nothing to
change, the file is left alone. If reindent does change a file, the changed
file is a fixed-point for future runs (i.e., running reindent on the
resulting .py file won't change it again).
The hard part of reindenting is figuring out what to do with comment
lines. So long as the input files get a clean bill of health from
tabnanny.py, reindent should do a good job.
The backup file is a copy of the one that is being reindented. The ".bak"
file is generated with shutil.copy(), but some corner cases regarding
user/group and permissions could leave the backup file more readable that
you'd prefer. You can always use the --nobackup option to prevent this.
"""
__version__ = "1"
import tokenize
import os, shutil
import sys
verbose = 0
recurse = 0
dryrun = 0
makebackup = True
def usage(msg=None):
if msg is not None:
print >> sys.stderr, msg
print >> sys.stderr, __doc__
def errprint(*args):
sep = ""
for arg in args:
sys.stderr.write(sep + str(arg))
sep = " "
sys.stderr.write("\n")
def main():
import getopt
global verbose, recurse, dryrun, makebackup
try:
opts, args = getopt.getopt(sys.argv[1:], "drnvh",
["dryrun", "recurse", "nobackup", "verbose", "help"])
except getopt.error, msg:
usage(msg)
return
for o, a in opts:
if o in ('-d', '--dryrun'):
dryrun += 1
elif o in ('-r', '--recurse'):
recurse += 1
elif o in ('-n', '--nobackup'):
makebackup = False
elif o in ('-v', '--verbose'):
verbose += 1
elif o in ('-h', '--help'):
usage()
return
if not args:
r = Reindenter(sys.stdin)
r.run()
r.write(sys.stdout)
return
for arg in args:
check(arg)
def check(file):
if os.path.isdir(file) and not os.path.islink(file):
if verbose:
print "listing directory", file
names = os.listdir(file)
for name in names:
fullname = os.path.join(file, name)
if ((recurse and os.path.isdir(fullname) and
not os.path.islink(fullname) and
not os.path.split(fullname)[1].startswith("."))
or name.lower().endswith(".py")):
check(fullname)
return
if verbose:
print "checking", file, "...",
try:
f = open(file)
except IOError, msg:
errprint("%s: I/O Error: %s" % (file, str(msg)))
return
r = Reindenter(f)
f.close()
if r.run():
if verbose:
print "changed."
if dryrun:
print "But this is a dry run, so leaving it alone."
if not dryrun:
bak = file + ".bak"
if makebackup:
shutil.copyfile(file, bak)
if verbose:
print "backed up", file, "to", bak
f = open(file, "w")
r.write(f)
f.close()
if verbose:
print "wrote new", file
return True
else:
if verbose:
print "unchanged."
return False
def _rstrip(line, JUNK='\n \t'):
"""Return line stripped of trailing spaces, tabs, newlines.
Note that line.rstrip() instead also strips sundry control characters,
but at least one known Emacs user expects to keep junk like that, not
mentioning Barry by name or anything <wink>.
"""
i = len(line)
while i > 0 and line[i-1] in JUNK:
i -= 1
return line[:i]
class Reindenter:
def __init__(self, f):
self.find_stmt = 1 # next token begins a fresh stmt?
self.level = 0 # current indent level
# Raw file lines.
self.raw = f.readlines()
# File lines, rstripped & tab-expanded. Dummy at start is so
# that we can use tokenize's 1-based line numbering easily.
# Note that a line is all-blank iff it's "\n".
self.lines = [_rstrip(line).expandtabs() + "\n"
for line in self.raw]
self.lines.insert(0, None)
self.index = 1 # index into self.lines of next line
# List of (lineno, indentlevel) pairs, one for each stmt and
# comment line. indentlevel is -1 for comment lines, as a
# signal that tokenize doesn't know what to do about them;
# indeed, they're our headache!
self.stats = []
def run(self):
tokenize.tokenize(self.getline, self.tokeneater)
# Remove trailing empty lines.
lines = self.lines
while lines and lines[-1] == "\n":
lines.pop()
# Sentinel.
stats = self.stats
stats.append((len(lines), 0))
# Map count of leading spaces to # we want.
have2want = {}
# Program after transformation.
after = self.after = []
# Copy over initial empty lines -- there's nothing to do until
# we see a line with *something* on it.
i = stats[0][0]
after.extend(lines[1:i])
for i in range(len(stats)-1):
thisstmt, thislevel = stats[i]
nextstmt = stats[i+1][0]
have = getlspace(lines[thisstmt])
want = thislevel * 4
if want < 0:
# A comment line.
if have:
# An indented comment line. If we saw the same
# indentation before, reuse what it most recently
# mapped to.
want = have2want.get(have, -1)
if want < 0:
# Then it probably belongs to the next real stmt.
for j in xrange(i+1, len(stats)-1):
jline, jlevel = stats[j]
if jlevel >= 0:
if have == getlspace(lines[jline]):
want = jlevel * 4
break
if want < 0: # Maybe it's a hanging
# comment like this one,
# in which case we should shift it like its base
# line got shifted.
for j in xrange(i-1, -1, -1):
jline, jlevel = stats[j]
if jlevel >= 0:
want = have + getlspace(after[jline-1]) - \
getlspace(lines[jline])
break
if want < 0:
# Still no luck -- leave it alone.
want = have
else:
want = 0
assert want >= 0
have2want[have] = want
diff = want - have
if diff == 0 or have == 0:
after.extend(lines[thisstmt:nextstmt])
else:
for line in lines[thisstmt:nextstmt]:
if diff > 0:
if line == "\n":
after.append(line)
else:
after.append(" " * diff + line)
else:
remove = min(getlspace(line), -diff)
after.append(line[remove:])
return self.raw != self.after
def write(self, f):
f.writelines(self.after)
# Line-getter for tokenize.
def getline(self):
if self.index >= len(self.lines):
line = ""
else:
line = self.lines[self.index]
self.index += 1
return line
# Line-eater for tokenize.
def tokeneater(self, type, token, (sline, scol), end, line,
INDENT=tokenize.INDENT,
DEDENT=tokenize.DEDENT,
NEWLINE=tokenize.NEWLINE,
COMMENT=tokenize.COMMENT,
NL=tokenize.NL):
if type == NEWLINE:
# A program statement, or ENDMARKER, will eventually follow,
# after some (possibly empty) run of tokens of the form
# (NL | COMMENT)* (INDENT | DEDENT+)?
self.find_stmt = 1
elif type == INDENT:
self.find_stmt = 1
self.level += 1
elif type == DEDENT:
self.find_stmt = 1
self.level -= 1
elif type == COMMENT:
if self.find_stmt:
self.stats.append((sline, -1))
# but we're still looking for a new stmt, so leave
# find_stmt alone
elif type == NL:
pass
elif self.find_stmt:
# This is the first "real token" following a NEWLINE, so it
# must be the first token of the next program statement, or an
# ENDMARKER.
self.find_stmt = 0
if line: # not endmarker
self.stats.append((sline, self.level))
# Count number of leading blanks.
def getlspace(line):
i, n = 0, len(line)
while i < n and line[i] == " ":
i += 1
return i
if __name__ == '__main__':
main()
【讨论】：