[Tutor] how to read two files and substitute

[Michiel Overtoom]

On 2011-05-17 15:42, lina wrote:

 > I want to get the $4(column 4) value which has  the $1 value. for
 > values in file2

Have you tried to write some code yourself already?  Please show it.

Anyway, I'd proceed with something like this:

mapping={}
for line in open("file1").readlines():
     parts=line.strip().split()
     mapping[parts[0]]=parts[3]
origs=open("file2").read().split()
print " ".join([mapping[orig] for orig in origs])

The output is "173 174 174". Since you provide no column names I can't 
use meaningful variable names. Are these very big files?  In that case 
another approach is maybe better.

Greetings,


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