Yosef Levy wrote:
> Hello All,
>
> I am running with Python 2.7
> I have to run script that could have get arguments in two ways:
> 1. argument + file name.
> 2. argument + input from pipe.
>
> example for 1:
> ./my_script.py -t 1,2,3 file_name.txt
>
> example for 2:
> grep snd file_name.txt | ./my_script.py -t 1,2,3
>
> I am using "parse_known_args" to parse the rest of args when pipe exists.
> and capture with: "fileinput".
>
> My problem is that this does not run always, for second option.
> Any idea how could I get standard input with additional flag?
> for example, running with pipe option will be like this:
> grep snd file_name.txt | ./my_script.py -t 1,2,3 -
> where the additional "-" at the end will indicate script to get standard
> input.
It's not clear to me why you use parse_known_args(). The examples you give
above seem to be covered by
$ cat tmp.py
#!/usr/bin/env python
import argparse
import fileinput
parser = argparse.ArgumentParser()
parser.add_argument("--tags", "-t")
parser.add_argument("files", metavar="file", nargs="*")
args = parser.parse_args()
print args.tags
for line in fileinput.input(args.files):
print line.strip()
$ cat greek.txt
alpha
beta
gamma
delta
$ cat numbers.txt
ONE
TWO
Reading from a file:
$ ./tmp.py -t 1,2,3 numbers.txt
1,2,3
ONE
TWO
Reading from two files:
$ ./tmp.py -t 1,2,3 numbers.txt greek.txt
1,2,3
ONE
TWO
alpha
beta
gamma
delta
Reading from stdin:
$ grep ^[ab] greek.txt | ./tmp.py -t 1,2,3
1,2,3
alpha
beta
Reading from a file, then stdin, then another file:
$ grep ^[ab] greek.txt | ./tmp.py -t 1,2,3 numbers.txt - numbers.txt
1,2,3
ONE
TWO
alpha
beta
ONE
TWO
$
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