Question

I have a file which contains mostly of names mapping to a certain list of numbers. I would like to parse this file, and I presume a regular expression would be good here. I have however two problems:

• The names can consist of either a word, or a word followed by more words, or a word with underscore. A word can also contain the following characters: (/->)

• There is a comment in the beginning of the file and at some other places which should not be included in the result. The comments are always a line of--- followed by some text followed by another line of ---

So if I have the following file

-----------------------------------
Comment
-----------------------------------
Ignore these lines
-----------------------------------
someVar                        0.0  1.0
some var with spaces           52   93
another var_with_underscores   3
some var with (special->chars) 13  37  95
another char/slash             132  
-----------------------------------
Another comment
-----------------------------------
yet another var               27.3  9

I want to return a dictionary

{"someVar": [0.0, 1.0], 
 "some var with spaces": [52, 93],
 "another var_with_underscores": [3],
 "another char/slash": [132]  
 "some var with (special->chars)": [13, 37, 95],
 "yet another var": [27.3, 9]}

If it’s too much to ask for one question, I would be happy just knowing the regexp.

I’m using Python 2.7.

Answer 1

This may do what you’re looking for:

import re

results = {}
with open('example.txt', 'r') as f:
    for line in f.readlines():
        m = re.match(r'([^\d]+)(.*)', line.strip())
        if m and m.group(2):
            results[m.group(1).strip()] = [float(n) for n in m.group(2).split()]

Which on your updated example give:

{'some var with (special->chars)': [13.0, 37.0, 95.0]
 'another var_with_underscores': [3.0]
 'some var with spaces': [52.0, 93.0]
 'someVar': [0.0, 1.0]
 'another char/slash': [132.0]
 'yet another var': [27.3, 9.0]}