Any algorithm to preserve whitespaces?

Peter Otten __peter__ at web.de
Thu Jan 24 04:30:54 EST 2013


Santosh Kumar wrote:

> On 1/24/13, Peter Otten <__peter__ at web.de> wrote:
>> Santosh Kumar wrote:
>>
>>> Yes, Peter got it right.
>>>
>>> Now, how can I replace:
>>>
>>>     script, givenfile = argv
>>>
>>> with something better that takes argv[1] as input file as well as
>>> reads input from stdin.
>>>
>>> By input from stdin, I mean that currently when I do `cat foo.txt |
>>> capitalizr` it throws a ValueError error:
>>>
>>>     Traceback (most recent call last):
>>>       File "/home/santosh/bin/capitalizr", line 16, in <module>
>>>         script, givenfile = argv
>>>     ValueError: need more than 1 value to unpack
>>>
>>> I want both input methods.
>>
>> You can use argparse and its FileType:
>>
>> import argparse
>> import sys
>>
>> parser = argparse.ArgumentParser()
>> parser.add_argument("infile", type=argparse.FileType("r"), nargs="?",
>> default=sys.stdin)
>> args = parser.parse_args()
>>
>> for line in args.infile:
>>     print line.strip().title() # replace with your code
>>
> 
> This works file when I do `script.py inputfile.txt`; capitalizes as
> expected. But it work unexpected if I do `cat inputfile.txt |
> script.py`; leaves the first word of each line and then capitalizes
> remaining.

I cannot reproduce that:

$ cat title.py 
#!/usr/bin/env python
import argparse
import sys

parser = argparse.ArgumentParser()
parser.add_argument("infile", type=argparse.FileType("r"), nargs="?",
default=sys.stdin)
args = parser.parse_args()

for line in args.infile:
    print line.strip().title() # replace with your code
$ cat inputfile.txt 
alpha beta
    gamma delta epsilon
zeta
$ cat inputfile.txt | ./title.py 
Alpha Beta
Gamma Delta Epsilon
Zeta
$ ./title.py inputfile.txt 
Alpha Beta
Gamma Delta Epsilon
Zeta





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