如何使用python从文本文件的行中读取特定字符？

Question

I have multiple .txt files that contain multiple lines similar to this:

[class1] 1:-28 9:-315 13:-354227 2:-36.247 17:-342 8:-34 14:-3825
[class2] 14:-31.8679 7:-32.3582 2:-32.4127 1:-32.7257 8:-32.9804 16:-33.2156

I want to know how to read the numbers before the : s and store them in an array.

Answer 1

>>> import re
>>> text = "[class1] 1:-28 9:-315 13:-354227 2:-36.247 17:-342 8:-34 14:-3825"
>>> map(int, re.findall(r'(\S+):\S+', text)) # You could also do map(float,...)
[1, 9, 13, 2, 17, 8, 14]

Answer 2

Or without using RE, if you know for sure the syntax of the file remains the same, you could use this:

>>> arr
['[class1] 1:-28 9:-315 13:-354227 2:-36.247 17:-342 8:-34 14:-3825', '[class2] 14:-31.8679 7:-32.3582 2:-32.4127 1:-32.7257 8:-32.9804 16:-33.2156']
>>> newArr = [map(lambda y: int(y[:y.index(":")]),x.split(" ")[1:]) for x in arr]
>>> newArr
[[1, 9, 13, 2, 17, 8, 14], [14, 7, 2, 1, 8, 16]]

---

UPDATE:

If you have several files, may be you would do something like this (based on @jamylak's clearer version of my solution):

[[[int(x.split(':')[0]) for x in line.split()[1:]] for line in open(fileName)] for fileName in fileNames]

where fileNames is the array of files you are speaking about

Answer 3

I would use regex but here is a version without, clearer than @Thrustmaster's solution imo.

>>> text = "[class1] 1:-28 9:-315 13:-354227 2:-36.247 17:-342 8:-34 14:-3825"
>>> [int(x.split(':')[0]) for x in text.split()[1:]]
[1, 9, 13, 2, 17, 8, 14]