如何使用pythonic方式（一个线性）在多个模式上拆分字符串？

Question

I am trying to extract file name from file pointer without extension. My file name is as follows:

this site:time.list , this.list , this site:time_sec.list , that site:time_sec.list and so on. Here required file name always precedes either whitespace or dot.

Currently I am doing this to get file from file name preceding white space and dot in file name.

search_term = os.path.basename(f.name).split(" ")[0]

and

search_term = os.path.basename(f.name).split(".")[0]

Expected file name output: this , this , this , that .

How can i combine above two into one liner kind and pythonic way?

Thanks in advance.

Answer 1

使用如下正则表达式， [ .]将在空格或点字符上分割

re.split('[ .]', os.path.basename(f.name))[0]

Answer 2

If you split on one and splitting on the other still returns something smaller, that's the one you want. If not, what you get is what you got from the first split. You don't need regex for this.

search_term = os.path.basename(f.name).split(" ")[0].split(".")[0]

Answer 3

Use regex to get the first word at the beginning of the string:

import re

re.match(r"\w+", "this site:time_sec.list").group()
# 'this'

re.match(r"\w+", "this site:time.list").group()
# 'this'

re.match(r"\w+", "that site:time_sec.list").group()
# 'that'

re.match(r"\w+", "this.list").group()
# 'this'

try this:

pattern = re.compile(r"\w+")
pattern.match(os.path.basename(f.name)).group()

---

Make sure your filenames don't have whitespace inside when you rely on the assumption that a whitespace separates what you want to extract from the rest. It's much more likely to get unexpected results you didn't think up in advance if you rely on implicit rules like that instead of actually looking at the strings you want to extract and tailor explicit expressions to fit the content.