预期的字符串或缓冲区(在re.sub中)

Question

我也看到了类似的问题(在这里,在这里)之前,SO,我知道这re.sub需要一个字符串(其中,我相信,我提供的),但我不知道什么是错在下面的代码:

tuples = re.findall(r'id":"(.*?)".*?name":"(.*?)"', response.text, re.DOTALL)
outfile = open("badEXtsWithIDs.csv", "wb")
print "Writing into CSV"
writer = csv.writer(outfile)
for entry in tuples:
    writeName = re.sub(r'\W', " ", entry)
    writer.writerow(writeName)

我认为这re.sub需要一个str变量,但是,不是进入str吗？我收到一个错误:TypeError: expected string or buffer就行了re.sub.任何帮助赞赏.

Answer 1

当您有多个匹配组时,re.findall返回listn- tuples:

re.findall('(foo).(bar)', 'foo foo bar foo|bar')
Out[5]: [('foo', 'bar'), ('foo', 'bar')]

因此,明确各自entry在tuples为一个tuple.当你传递tuple给re.sub,好吧,它抱怨.

tuples = re.findall('(foo).(bar)', 'foo foo bar foo|bar')

for entry in tuples:
    re.sub('oo','ox',entry)

...
/usr/lib/python3.3/re.py in sub(pattern, repl, string, count, flags)
    168     a callable, it's passed the match object and must return
    169     a replacement string to be used."""
--> 170     return _compile(pattern, flags).sub(repl, string, count)
    171 
    172 def subn(pattern, repl, string, count=0, flags=0):

TypeError: expected string or buffer

所以,做点别的.也许用map:

for entry in tuples:
    print(' '.join(map(lambda s: re.sub('oo','ox',s),entry)))

fox bar
fox bar

或者更容易理解

writer.writerow([re.sub(r'\W', " ",s) for s in entry])

等等