Reading a text file from standard input using <
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0
down vote
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I have a Python script which ends the following way:
if __name__ == "__main__":
if len(sys.argv) == 2:
file = open(sys.argv[1])
text = file.readline()
... #more statements
This works when I type in the following: $ python3 script.py my_file.txt
However, I want to change it so my script can accept text from standard input (or even a text file). This is what I want to be able to do:
$ ./script.py < my_file.txt
I think I need to use sys.stdin.read() (or maybe sys.stdin.readlines()). Could you tell me what I would need to change from my original script?
I'm sorry if this looks very basic, but I'm new to Python and I find it hard to see the difference.
python
asked Nov 9 at 18:04
Me All
1207
add a comment |
up vote
0
down vote
favorite
I have a Python script which ends the following way:
if __name__ == "__main__":
if len(sys.argv) == 2:
file = open(sys.argv[1])
text = file.readline()
... #more statements
This works when I type in the following: $ python3 script.py my_file.txt
However, I want to change it so my script can accept text from standard input (or even a text file). This is what I want to be able to do:
$ ./script.py < my_file.txt
I think I need to use sys.stdin.read() (or maybe sys.stdin.readlines()). Could you tell me what I would need to change from my original script?
I'm sorry if this looks very basic, but I'm new to Python and I find it hard to see the difference.
python
asked Nov 9 at 18:04
Me All
1207
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I have a Python script which ends the following way:
if __name__ == "__main__":
if len(sys.argv) == 2:
file = open(sys.argv[1])
text = file.readline()
... #more statements
This works when I type in the following: $ python3 script.py my_file.txt
However, I want to change it so my script can accept text from standard input (or even a text file). This is what I want to be able to do:
$ ./script.py < my_file.txt
I think I need to use sys.stdin.read() (or maybe sys.stdin.readlines()). Could you tell me what I would need to change from my original script?
I'm sorry if this looks very basic, but I'm new to Python and I find it hard to see the difference.
python
asked Nov 9 at 18:04
Me All
1207
I have a Python script which ends the following way:
if __name__ == "__main__":
if len(sys.argv) == 2:
file = open(sys.argv[1])
text = file.readline()
... #more statements
This works when I type in the following: $ python3 script.py my_file.txt
However, I want to change it so my script can accept text from standard input (or even a text file). This is what I want to be able to do:
$ ./script.py < my_file.txt
I think I need to use sys.stdin.read() (or maybe sys.stdin.readlines()). Could you tell me what I would need to change from my original script?
I'm sorry if this looks very basic, but I'm new to Python and I find it hard to see the difference.
python
python
asked Nov 9 at 18:04
Me All
1207
asked Nov 9 at 18:04
Me All
1207
asked Nov 9 at 18:04
Me All
1207
asked Nov 9 at 18:04
Me All
1207
asked Nov 9 at 18:04
Me All
1207
1207
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
up vote
1
down vote
accepted
It's exactly what you said, you don't need to open a file.
Instead of calling file.readline(), call sys.stdin.readline().
You can make it "nice", with something like:
file = sys.stdin if use_stdin else open(sys.argv[1])
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
Would I still need to leaveif len(sys.argv) == 2:? Or can I delete this part?
– Me All
Nov 9 at 18:08
It may be that the flaguse_stdinshould be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.
– Matthieu Brucher
Nov 9 at 18:11
add a comment |
up vote
0
down vote
Theres a cool module you can use for this! Assuming you want to do processing per line:
import fileinput
for line in fileinput.input():
process_line(line)
answered Nov 9 at 18:09
LeKhan9
921112
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
accepted
It's exactly what you said, you don't need to open a file.
Instead of calling file.readline(), call sys.stdin.readline().
You can make it "nice", with something like:
file = sys.stdin if use_stdin else open(sys.argv[1])
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
Would I still need to leaveif len(sys.argv) == 2:? Or can I delete this part?
– Me All
Nov 9 at 18:08
It may be that the flaguse_stdinshould be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.
– Matthieu Brucher
Nov 9 at 18:11
add a comment |
up vote
1
down vote
accepted
It's exactly what you said, you don't need to open a file.
Instead of calling file.readline(), call sys.stdin.readline().
You can make it "nice", with something like:
file = sys.stdin if use_stdin else open(sys.argv[1])
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
Would I still need to leaveif len(sys.argv) == 2:? Or can I delete this part?
– Me All
Nov 9 at 18:08
It may be that the flaguse_stdinshould be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.
– Matthieu Brucher
Nov 9 at 18:11
add a comment |
up vote
1
down vote
accepted
up vote
1
down vote
accepted
It's exactly what you said, you don't need to open a file.
Instead of calling file.readline(), call sys.stdin.readline().
You can make it "nice", with something like:
file = sys.stdin if use_stdin else open(sys.argv[1])
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
It's exactly what you said, you don't need to open a file.
Instead of calling file.readline(), call sys.stdin.readline().
You can make it "nice", with something like:
file = sys.stdin if use_stdin else open(sys.argv[1])
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
answered Nov 9 at 18:06
Matthieu Brucher
10.5k21935
10.5k21935
Would I still need to leaveif len(sys.argv) == 2:? Or can I delete this part?
– Me All
Nov 9 at 18:08
It may be that the flaguse_stdinshould be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.
– Matthieu Brucher
Nov 9 at 18:11
add a comment |
Would I still need to leaveif len(sys.argv) == 2:? Or can I delete this part?
– Me All
Nov 9 at 18:08
It may be that the flaguse_stdinshould be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.
– Matthieu Brucher
Nov 9 at 18:11
Would I still need to leave
if len(sys.argv) == 2:? Or can I delete this part?– Me All
Nov 9 at 18:08
Would I still need to leave
if len(sys.argv) == 2:? Or can I delete this part?– Me All
Nov 9 at 18:08
It may be that the flag
use_stdin should be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.– Matthieu Brucher
Nov 9 at 18:11
It may be that the flag
use_stdin should be len(sys.argv) != 2 ;) The flag should be whatever you need to decide between file input or standard input.– Matthieu Brucher
Nov 9 at 18:11
add a comment |
up vote
0
down vote
Theres a cool module you can use for this! Assuming you want to do processing per line:
import fileinput
for line in fileinput.input():
process_line(line)
answered Nov 9 at 18:09
LeKhan9
921112
add a comment |
up vote
0
down vote
Theres a cool module you can use for this! Assuming you want to do processing per line:
import fileinput
for line in fileinput.input():
process_line(line)
answered Nov 9 at 18:09
LeKhan9
921112
add a comment |
up vote
0
down vote
up vote
0
down vote
Theres a cool module you can use for this! Assuming you want to do processing per line:
import fileinput
for line in fileinput.input():
process_line(line)
answered Nov 9 at 18:09
LeKhan9
921112
Theres a cool module you can use for this! Assuming you want to do processing per line:
import fileinput
for line in fileinput.input():
process_line(line)
answered Nov 9 at 18:09
LeKhan9
921112
answered Nov 9 at 18:09
LeKhan9
921112
answered Nov 9 at 18:09
LeKhan9
921112
answered Nov 9 at 18:09
LeKhan9
921112
921112
add a comment |
add a comment |
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