File Sorting in Python

Question

I would like to sort a file in Python based on numerical values:

My input file looks like this:

66135 - A
65117 - B
63301 - C
63793 - D

Answer 1

Here is a complete code for that.

with open('inputFileName') as fp:
    lst = map(lambda s:s.rstrip(), fp.readlines())

with open('outputFileName', 'w') as fp:
    fp.write("\n".join(sorted(lst, key=lambda s:int(s.split()[0]))))