如何在字符串包含元字符时使用“re”包从python中的字符串中查找和替换整个单词（完全匹配）？

Question

例如，

line = "array[0] is the first element, array[0]some_character, is not a valid element"

我只想在字符串中查找并替换"array[0]"。在这种情况下，假设我想用单词"element1" 替换它。那么输出应该如下：

line = "element1 is the first element, array[0]some_character, is not a valid element".

请注意，在字符串中，array[0]some_character 应该保持不变，而不应该像"element1some_character" 那样被替换

感谢任何人的帮助。

Answer 1

尝试关注

word = "abcd ab[0]c ab[0] class ab[0]d classified ab[0]"
re.sub(r'ab\[0\](\s|$)', r'ahmed\1', word)

输出：

'abcd ab[0]c ahmed class ab[0]d classified ahmed'

或使用前瞻

word = "abcd ab[0]c ab[0] class ab[0]d classified ab[0]"
re.sub(r'ab\[0\](?=\s|$)', r'ahmed', word)

输出：

'abcd ab[0]c ahmed class ab[0]d classified ahmed'

Answer 2

t = "array[0] is the first element, array[0]some_character, is not a valid element" re.sub("a[a-z]+\[[0-9]+\](?=[\s]{1})", "Element1", t)

您在正则表达式的末尾看到 - (?=[\s]{1})，第二个数组 [0] 后面没有空格，因此不会被替换。

Answer 3

import re

line = "array[0] is the first element, second is array[0], array[0]some_character, is not valid element array[0]."
res = re.sub(r'\barray\[0\](?!\w)', 'REPL', line)
print res

输出：

REPL is the first element, second is REPL, array[0]some_character, is not valid element REPL.

说明：

\b              # word boundary, to not match isarray[0]
array\[0\]      # the string to match
(?!\w)          # negative lookahead, make sure we haven't a word character after

Demo & explanation

Answer 4

import re

line = "array[0] is the first element, array[0]some_character, is not a valid element"
re.sub('array\[0\]\s','element1 ',line)

输出： 'element1 是第一个元素，array[0]some_character，不是有效元素'