joining files

[Dave Angel]

(You forgot to include the python-list in your response.  So it only 
went to me.  Normally, you just do reply-all to the message)

mannu jha wrote:
> On Sun, 16 May 2010 13:52:31 +0530  wrote
>   
>> mannu jha wrote:
>>     
>
>   
>> Hi,
>>     
>
>   
>
>   
>> I have few files like this:
>> file1:
>> 22 110.1 
>> 33 331.5 22.7 
>> 5 271.9 17.2 33.4
>> 4 55.1 
>>     
>
>   
>> file1 has total 4 column but some of them are missing in few row.
>>     
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>   
>> file2:
>> 5 H
>> 22 0
>>     
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>   
>> file3:
>> 4 T
>> 5 B
>> 22 C
>> 121 S
>>     
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>   
>
>   
>> in all these files first column is the main source of matching their entries. So What I want in the output is only those entries which is coming in all three files.
>>     
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>> output required:
>>     
>
>   
>> 5 271.9 17.2 33.4 5 H 5 T
>> 22 110.1     22 0 22 C
>>     
>
>   
> I am trying with this :
>
> from collections import defaultdict
>
> def merge(sources):
>     blanks = [blank for items, blank, keyfunc in sources]
>     d = defaultdict(lambda: blanks[:])
>     for index, (items, blank, keyfunc) in enumerate(sources):
>         for item in items:
>             d[keyfunc(item)][index] = item
>     for key in sorted(d):
>         yield d[key]
>
> if __name__ == "__main__":
>     a = open("input1.txt")
>     
>     c = open("input2.txt")
>
>     def key(line):
>         return line[:2]
>     def source(stream, blank="", key=key):
>         return (line.strip() for line in stream), blank, key
>     for m in merge([source(x) for x in [a,c]]):
>         print "|".join(c.ljust(10) for c in m)
>
> but with input1.txt:
> 187    7.79   122.27   54.37   4.26   179.75
> 194    8.00   121.23   54.79   4.12   180.06
> 15    8.45   119.04   55.02   4.08   178.89
> 176    7.78   118.68   54.57   4.20   181.06
> 180    7.50   119.21   53.93      179.80
> 190    7.58   120.44   54.62   4.25   180.02
> 152    8.39   120.63   55.10   4.15   179.10
> 154    7.79   119.62   54.47   4.22   180.46
> 175    8.42   120.50   55.31   4.04   180.33
> and input2.txt:
>  15   H 
>  37   H 
>  95   T
> 124   H 
> 130   H 
> 152   H 
> 154   H 
> 158   H 
> 164   H
> 175   H 
> 176   H 
> 180   H
> 187   H 
> 190   T
> 194   C
> 196   H 
> 207   H 
> 210   H 
> 232   H 
> it is giving output as:
>           |
>           |124   H
>           |130   H
> 154    7.79   119.62   54.47   4.22   180.46|158   H
>           |164   H
> 175    8.42   120.50   55.31   4.04   180.33|176   H
> 180    7.50   119.21   53.93      179.80|187   H
> 190    7.58   120.44   54.62   4.25   180.02|196   H
>           |207   H
>           |210   H
>           |232   H
>           |37   H
>           |95   T
> so it not matching it properly, can anyone please suggest where I am doing mistake.
>
>
>
>   
I'm about to travel all day, so my response will be quite brief.

Not sure what you mean by the blank and key values that source() takes, 
since they're just passed on to its return value.

I don't see any place where you compare the items from the various 
files, so you aren't checking if an item is in multiple files.

DaveA