ValueError: 转换表的长度必须为 256 个字符

Question

我有 python 烧瓶项目（程序），我将用户输入的带有大写字母和标点符号的字符串转换为没有它们的字符串。当我运行程序时，我收到以下错误：ValueError: translation table must be 256 characters long Traceback (most recent call last) File:"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line2463, in __call__ return self.wsgi_app(environ, start_response) File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line2449, in wsgi_app response = self.handle_exception(e) File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line1866, in handle_exception reraise(exc_type, exc_value, tb) File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line2446, in wsgi_app response = self.full_dispatch_request() File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line1951, in full_dispatch_request rv = self.handle_user_exception(e) File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line1820, in handle_user_exception reraise(exc_type, exc_value, tb) File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line1949, in full_dispatch_request rv = self.dispatch_request() File"/home/sd18656/.local/lib/python2.7/site-packages/flask/app.py", line1935, in dispatch_request returnself.view_functions[rule.endpoint](**req.view_args) File"/home/sd18656/FlaskProject/mainapp.py", line 61, in home score,total_processed_data = get_score(abstract) File"/home/sd18656/FlaskProject/mainapp.py", line 32, in get_scoreabstract = abstract.translate(string.punctuation).lower()在程序中，abstract 是一个字符串类型。我遇到了这个解决方案：string.translate 函数中的“表”是什么意思？但是，对于该错误，orstring.maketrans似乎并不顺利。我该如何解决这个问题？lower()upper()

Answer 1

您需要将转换表传递给str.translate（string.translate在 Python 2 中）。翻译表无非是一个dictwherekey是搜索字符并且value是替换字符， wherekey和value是ord()各个字符的 the。

例如，如果您想punctuation用空格替换所有字符，请执行以下操作：

from string import punctuation

transtable = string.maketrans(punctuation, ' ' * len(punctuation))

abstract = abstract.translate(transtable).lower()

这是一个概念证明：

>>> from string import punctuation

>>> transtable = string.maketrans(punctuation, ' ' * len(punctuation))

>>> type(transtable)

<class 'dict'>

>>> 'This!is#a.string,with;punctuations:'.translate(transtable).lower()

'this is a string with punctuations '

>>> 

这是maketrans和的另一个用法示例translate（只是为了好玩）：

>>> elite = string.maketrans('aeiou', '4310v')

>>> 'Hackers Rulez'.translate(elite)

'H4ck3rs Rvl3z'

>>>