blob: ae85d918ad73b4c2911784da2cdf95145d93df21 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
Documentation
=============
.. toctree::
:maxdepth: 2
argparse-vs-optparse
overview
api-docs
Example usage
=============
The following simple example uses the argparse module to generate the command-line interface for a Python program that sums its command-line arguments and writes them to a log file::
import argparse
import sys
if __name__ == '__main__':
# create the parser
parser = argparse.ArgumentParser(
description='Sum the integers on the command line.')
# add the arguments
parser.add_argument(
'integers', metavar='int', type=int, nargs='+',
help='one of the integers to be summed')
parser.add_argument(
'--log', type=argparse.FileType('w'), default=sys.stdout,
help='the file where the sum should be written '
'(default: write the sum to stdout)')
# parse the command line
args = parser.parse_args()
# write out the sum
args.log.write('%s\n' % sum(args.integers))
args.log.close()
Assuming the Python code above is saved into a file called ``scriptname.py``, it can be run at the command line and provides useful help messages::
$ scriptname.py -h
usage: scriptname.py [-h] [--log LOG] int [int ...]
Sum the integers on the command line.
positional arguments:
int one of the integers to be summed
optional arguments:
-h, --help show this help message and exit
--log LOG the file where the sum should be written (default: write the sum
to stdout)
When run with the appropriate arguments, it writes the sum of the command-line integers to the specified log file::
$ scriptname.py --log=log.txt 1 1 2 3 5 8
$ more log.txt
20
|
