如何在Python字符串中替换括号及其中的文本

我有两个这样的字符串。

string1 = "Today I went to the (market) to pick up some (fruit)."
string2 = "Today I went to (school) to learn (algebra) and science."

我想根据以下字典删除并替换两个字符串中的括号和括号内的文本。

word_dict = {'market': 'library', 'fruit': 'books', 'school': 'class', 'algebra': 'calculus'};

我希望新的字符串是：

string1 = "Today I went to the library to pick up some books."
string2 = "Today I went to class to learn calculus and science."

为了做到这一点，我需要捕获括号内的文本，以便我可以使用它作为获取字典中的值的键。然后我需要用该值替换括号和文本。我在使用正则表达式以及如何执行此操作时遇到问题。

你可以使用str.replace() https://docs.python.org/2/library/string.html#string.replace:

string1 = "Today I went to the (market) to pick up some (fruit)."
string2 = "Today I went to (school) to learn (algebra) and science."
word_dict = {'market': 'library', 'fruit': 'books', 'school': 'class', 'algebra': 'calculus'}

for word, translation in word_dict.items():  # Use word_dict.iteritems() for Python 2
    string1 = string1.replace('(' + word + ')', translation)
    string2 = string2.replace('(' + word + ')', translation)

你也可以使用str.format() https://docs.python.org/2/library/string.html#string.Formatter.format如果你可以控制要使用的初始字符串{}代替():

string1 = "Today I went to the {market} to pick up some {fruit}."
string2 = "Today I went to {school} to learn {algebra} and science."
word_dict = {'market': 'library', 'fruit': 'books', 'school': 'class', 'algebra': 'calculus'}

string1 = string1.format(**word_dict)
string2 = string2.format(**word_dict)

如果您无法控制初始输出，但想使用str.format()无论如何，你可以替换任何出现的( and ) with { and }:

string1 = string1.replace('(', '{').replace(')', '}').format(**word_dict)
string2 = string2.replace('(', '{').replace(')', '}').format(**word_dict)

或者以更简洁的方式执行相同操作，您可以使用str.translate() https://docs.python.org/2/library/string.html#string.translate随着str.maketrans() https://docs.python.org/2/library/string.html#string.maketrans:

trd = str.maketrans('()', '{}')
string1 = string1.translate(trd).format(**word_dict)
string2 = string2.translate(trd).format(**word_dict)

请记住，这将用大括号替换所有括号，即使它们没有包围您要替换的单词。您可以使用反向翻译剩余的大括号rev_trd = str.maketrans('{}', '()')格式化字符串后；但通常在那时你最好只使用for循环和str.replace()如第一段代码所示。除非您可以将初始字符串更改为仅包含大括号，否则请使用它。