使用re.sub替换第二个和最后一个第二个字符

Question

I have a string "F(foo)" , and I'd like to replace that string with "F('foo')" . I know we can also use regular expression in the second parameter and do this replacement using re.sub(r"F\\(foo\\)", r"F\\('foo'\\)",str) . But the problem here is, foo is a dynamic string variable. It is different every time we want to do this replacement. Is it possible by some sort of regex, to do such replacement in a cleaner way?

I remember one way to extract foo using () and then .group(1) . But this would require me to define one more temporary variable just to store foo. I'm curious if there is a way by which we can replace "F(foo)" with "F('foo')" in a single line or in other words in a more cleaner way.

Examples :

F(name) should be replaced with F('name') . F(id) should be replaced with F('id') . G(name) should not be replaced. So, the regex would be r"F\\((\\w)+\\)" to find such strings.

Answer 1

Using re.sub

Ex:

import re

s = "F(foo)"
print(re.sub(r"\((.*)\)", r"('\1')", s))

Output:

F('foo')

Answer 2

The following regex encloses valid [Python|C|Java] identifiers after F and in parentheses in single quotation marks:

re.sub(r"F\(([_a-z][_a-z0-9]+)\)", r"F('\1')", s, flags=re.I)
#"F('foo')"

Answer 3

There are several ways, depending on what foo actually is. If it can't contain ( or ) , you can just replace ( with (' and ) with ') . Otherwise, try using

re.sub(r"F\((.*)\)", r"F('\1')", yourstring)

where the \\1 in the replacement part will reference the (.*) capture group in the search regex

Answer 4

In your pattern F\\((\\w)+\\) you are almost there, you just need to put the quantifier + after the \\w to repeat matching 1+ word characters.

If you put it after the capturing group, you repeat the group which will give you the value of the last iteration in the capturing group which would be the second o in foo.

You could update your expression to:

F\((\w+)\)

And in the replacement refer to the capturing group using \\1

F('\1')

For example:

import re
str = "F(foo)"
print(re.sub(r"F\((\w+)\)", r"F('\1')", str)) # F('foo')

Python demo