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]))))

Answer 2

f2.writelines(sorted(f1, key=lambda line:int(line.split()[0])))

where f2 is your output file and f1 is your input file.

Answer 3

you can try this way

with open('filename','r') as file:
    # spilt() the line with '-'
    lis=[line.strip().split('-') for line in file]
    # sort the lis using the values
    print sorted(lis,key=lambda x:int(x[0].strip()))