Question

假设我有以下字符串，

ing = "2 cup butter, softened"

我只希望字符串中有butter（到目前为止我已完成以下操作），

ing.replace('2','').replace('cup','').replace(', ','').replace('softened','')
ing.strip()

修改

    Traceback (most recent call last):
  File "parsley.py", line 107, in <module>
    leaf.write_ingredients_to_csv()
  File "parsley.py", line 91, in write_ingredients_to_csv
    out = re.sub(words, '', matched)
  File "C:\Users\Nikhil\Anaconda3\lib\re.py", line 191, in sub
    return _compile(pattern, flags).sub(repl, string, count)
  File "C:\Users\Nikhil\Anaconda3\lib\re.py", line 301, in _compile
    p = sre_compile.compile(pattern, flags)
  File "C:\Users\Nikhil\Anaconda3\lib\sre_compile.py", line 562, in compile
    p = sre_parse.parse(p, flags)
  File "C:\Users\Nikhil\Anaconda3\lib\sre_parse.py", line 855, in parse
    p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, 0)
  File "C:\Users\Nikhil\Anaconda3\lib\sre_parse.py", line 416, in _parse_sub
    not nested and not items))
  File "C:\Users\Nikhil\Anaconda3\lib\sre_parse.py", line 752, in _parse
    len(char) + 1)
sre_constants.error: unknown extension ?| at position 23

在Python 3中有更有效的方法吗？我所展示的只是我正在处理的字符串的一个示例。我还需要删除更多包含不同字词的字符串，例如cups，cup，tablespoons和teaspoon。我使用相同的方法来消除字符串中的单词，那么有更好的方法吗？

Answer 1

您可能想要使用正则表达式。

import re

words = r'oz|lbs?|cups?|tablespoons?|tea‌spoons?|softened'
words_rm = r'slices?|shredded|sheets?|cans?|\d ?g\b'
other = r'[\d,;#\(\)\[\]\.]'
ing = "2 cup butter, softened"
out = re.sub(words, '', ing)
out = re.sub(words_rm, '', out)
out = re.sub(other, '', out)
out.strip()
# returns:
'butter'

Answer 2

Regular Expressions对于解析字符串非常有用。使用它们，您可以搜索所需的字符串匹配的所有时间，并从中创建一个新的字符串。

从字符串中删除特定单词的最有效方法

2 个答案: