如何编写Unix管道风格的Python代码(1)(2)

find logdir -name "access-log*" | \
xargs cat | \
grep '[^-]$' | \
awk '{ total += $NF } END { print total }'

def find(topdir, filepat, processfunc):
    files = []
    for path, dirlist, filelist in os.walk(top):
        for name in fnmatch.filter(filelist, filepat):
            files.append(name)
    return files
 
 def cat(files):
    lines = []
    for file in files:
        with open(file) as f:
            for line in f:
                lines.append(line)
    return lines
 
 def grep(pattern, lines):
    result = []
    import re
    pat = re.compile(pattern)
    for line in lines:
        if pat.search(line):
            result.append(line)
    resurn result
 
lines = grep('[^-]$', cat(find('logdir', 'access-log*')))
col = (line.rsplit(None, 1)[1] for line in lines)
print sum(int(c) for c in col)