通过python实现linux中的wc命令，学习python参数处理模块optparse
#!/usr/bin/env python
# coding=utf-8
import sys, os
from optparse import OptionParser
def opt():
parser = OptionParser()
parser.add_option("-c", "--char",
dest="chars",
action="store_true",
default=False,
help="only count chars")
parser.add_option("-w", "--ward",
dest="words",
action="store_true",
default=False,
help="only count words")
parser.add_option("-l", "--line",
dest="lines",
action="store_true",
default=False,
help="only count lines")
parser.add_option("-n", "--no-total",
dest="nototal",
action="store_true",
default=False,
help="show total or not")
options, args = parser.parse_args()
return options, args
def get_count(data):
chars = len(data)
words = len(data.split())
lines = data.count(‘\n‘)
return lines, words, chars
def print_wc(options, lines, words, chars, fn):
if options.lines:
print lines,
if options.words:
print words,
if options.chars:
print chars,
print(fn)
def main():
options, args = opt()
if not (options.words or options.chars or options.lines):
options.words, options.chars, options.lines = True, True, True
if args:
total_lines, total_words, total_chars = 0, 0, 0
for fn in args:
if os.path.isfile(fn):
with open(fn) as fd:
data = fd.read()
lines, words, chars = get_count(data)
print_wc(options, lines, words, chars, fn)
total_lines += lines
total_words += words
total_chars += chars
elif os.path.isdir(fn):
print("%s: is a directory" % fn, file=sys.stderr)
else:
sys.stderr.write("%s: No such file or direcotry\n" % fn)
if len(args) > 1 and not options.nototal:
print_wc(options, total_lines, total_words, total_chars, ‘total‘)
else:
data = sys.stdin.read()
fn = ‘‘
lines, words, chars = get_count(data)
print_wc(options, lines, words, chars, fn)
if __name__ == ‘__main__‘:
main()原文：http://xtbao.blog.51cto.com/7482722/1889772