Translate argparse's internal strings

问题

How can I translate Python's argparse module strings?

For example, when you display the help, it says "usage: ", string that is translatable but I don't know how to do it in my program.

This is the source code part of argparse.py:

def _format_usage(self, usage, actions, groups, prefix):
        if prefix is None:
            prefix = _('usage: ')

I couldn't trace the way to set this prefix, I think this is internal.

I don't want to have to append a .mo file to somewhere in the system. Ideally the translation should live in my program directory, or better in the source code.

Any help would be much appreciated.

回答1:

Running the following:

import argparse

class MyHelpFormatter(argparse.HelpFormatter):
    def __init__(self, *args, **kwargs):
        super(MyHelpFormatter, self).__init__(*args, **kwargs)

    def _format_usage(self, usage, actions, groups, prefix):
        return super(MyHelpFormatter, self)._format_usage(
            usage, actions, groups, prefix if prefix else "bla: ")

class MyArgumentParser(argparse.ArgumentParser):
    def __init__(self, *args, **kwargs):
        kwargs['formatter_class']=MyHelpFormatter
        super(MyArgumentParser, self).__init__(*args, **kwargs)


p = MyArgumentParser(description='Foo')
p.add_argument('foo', type=str)
print p.parse_args()

prints

python myargparse.py  --help
bla: myargparse.py [-h] foo

Foo

positional arguments:
  foo

optional arguments:
  -h, --help  show this help message and exit

_('usage: ') references gettext. In argparse.py, at the top, you have:

from gettext import gettext as _

You can muck around with gettext a bit.

Given a .po file:

msgid "usage: "
msgstr "foobar: "

You can convert it to a .mo file (for example here).

Afterwards (where ./foo/LC_MESSAGES/messages.mo is the result of compiling the .po):

~/Desktop> find . -name *mo
./foo/LC_MESSAGES/messages.mo
~/Desktop> cat myargparse2.py
import argparse
import gettext
gettext.bindtextdomain(gettext.textdomain(), '.')
p = argparse.ArgumentParser(description='Foo')
p.add_argument('foo', type=str)
print p.parse_args()
~/Desktop> LANGUAGE=foo python myargparse2.py
foobar: myargparse2.py [-h] foo
myargparse2.py: error: too few arguments

Use your desired languages instead of foo.

回答2:

Based on Vlad's answer, I made it shorter:

class CustomHelpFormatter(argparse.HelpFormatter):
    def __init__(self, *args, **kwargs):
        super(CustomHelpFormatter, self).__init__(*args, **kwargs)

    def _format_usage(self, usage, actions, groups, prefix):
        return super(CustomHelpFormatter, self)._format_usage(
            usage, actions, groups, prefix if prefix else "Uso: ")


if __name__ == "__main__":

    parser = argparse.ArgumentParser(prog="jcheq.py",
                                     usage="%(prog)s [opciones] [paths...]\nThe paths are optional; if not given . is "
                                           "used.",
                                     add_help=False,
                                     formatter_class=CustomHelpFormatter)

来源：https://stackoverflow.com/questions/34614550/translate-argparses-internal-strings

标签

python

python-3.x

argparse