python-docs-pl/howto/argparse.po at 3.9 · python/python-docs-pl

408 lines (324 loc) · 11.9 KB
# SOME DESCRIPTIVE TITLE.
# Copyright (C) 2001-2021, Python Software Foundation
# This file is distributed under the same license as the Python package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
# Translators:
# Seweryn Piórkowski <seweryn.piorkowski@gmail.com>, 2020
"Project-Id-Version: Python 3.9\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2021-01-01 05:02+0000\n"
"PO-Revision-Date: 2017-02-16 17:44+0000\n"
"Last-Translator: Seweryn Piórkowski <seweryn.piorkowski@gmail.com>, 2020\n"
"Language-Team: Polish (https://www.transifex.com/python-doc/teams/5390/pl/)\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Language: pl\n"
"Plural-Forms: nplurals=4; plural=(n==1 ? 0 : (n%10>=2 && n%10<=4) && "
"(n%100<12 || n%100>14) ? 1 : n!=1 && (n%10>=0 && n%10<=1) || (n%10>=5 && "
"n%10<=9) || (n%100>=12 && n%100<=14) ? 2 : 3);\n"
msgid "Argparse Tutorial"
msgid "author"
msgstr "autor"
msgid "Tshepang Lekhonkhobe"
"This tutorial is intended to be a gentle introduction to :mod:`argparse`, "
"the recommended command-line parsing module in the Python standard library."
"There are two other modules that fulfill the same task, namely :mod:`getopt` "
"(an equivalent for :c:func:`getopt` from the C language) and the deprecated :"
"mod:`optparse`. Note also that :mod:`argparse` is based on :mod:`optparse`, "
"and therefore very similar in terms of usage."
msgid "Concepts"
"Let's show the sort of functionality that we are going to explore in this "
"introductory tutorial by making use of the :command:`ls` command:"
msgid "A few concepts we can learn from the four commands:"
"The :command:`ls` command is useful when run without any options at all. It "
"defaults to displaying the contents of the current directory."
"If we want beyond what it provides by default, we tell it a bit more. In "
"this case, we want it to display a different directory, ``pypy``. What we "
"did is specify what is known as a positional argument. It's named so because "
"the program should know what to do with the value, solely based on where it "
"appears on the command line. This concept is more relevant to a command "
"like :command:`cp`, whose most basic usage is ``cp SRC DEST``. The first "
"position is *what you want copied,* and the second position is *where you "
"want it copied to*."
"Now, say we want to change behaviour of the program. In our example, we "
"display more info for each file instead of just showing the file names. The "
"``-l`` in that case is known as an optional argument."
"That's a snippet of the help text. It's very useful in that you can come "
"across a program you have never used before, and can figure out how it works "
"simply by reading its help text."
msgid "The basics"
msgid "Let us start with a very simple example which does (almost) nothing::"
msgid "Following is a result of running the code:"
msgid "Here is what is happening:"
"Running the script without any options results in nothing displayed to "
"stdout. Not so useful."
"The second one starts to display the usefulness of the :mod:`argparse` "
"module. We have done almost nothing, but already we get a nice help message."
"The ``--help`` option, which can also be shortened to ``-h``, is the only "
"option we get for free (i.e. no need to specify it). Specifying anything "
"else results in an error. But even then, we do get a useful usage message, "
"also for free."
msgid "Introducing Positional arguments"
msgid "An example::"
msgid "And running the code:"
msgid "Here is what's happening:"
"We've added the :meth:`add_argument` method, which is what we use to specify "
"which command-line options the program is willing to accept. In this case, "
"I've named it ``echo`` so that it's in line with its function."
msgid "Calling our program now requires us to specify an option."
"The :meth:`parse_args` method actually returns some data from the options "
"specified, in this case, ``echo``."
"The variable is some form of 'magic' that :mod:`argparse` performs for free "
"(i.e. no need to specify which variable that value is stored in). You will "
"also notice that its name matches the string argument given to the method, "
"``echo``."
"Note however that, although the help display looks nice and all, it "
"currently is not as helpful as it can be. For example we see that we got "
"``echo`` as a positional argument, but we don't know what it does, other "
"than by guessing or by reading the source code. So, let's make it a bit more "
msgid "And we get:"
msgid "Now, how about doing something even more useful::"
"That didn't go so well. That's because :mod:`argparse` treats the options we "
"give it as strings, unless we tell it otherwise. So, let's tell :mod:"
"`argparse` to treat that input as an integer::"
"That went well. The program now even helpfully quits on bad illegal input "
"before proceeding."
msgid "Introducing Optional arguments"
"So far we have been playing with positional arguments. Let us have a look on "
"how to add optional ones::"
msgid "And the output:"
"The program is written so as to display something when ``--verbosity`` is "
"specified and display nothing when not."
"To show that the option is actually optional, there is no error when running "
"the program without it. Note that by default, if an optional argument isn't "
"used, the relevant variable, in this case :attr:`args.verbosity`, is given "
"``None`` as a value, which is the reason it fails the truth test of the :"
"keyword:`if` statement."
msgid "The help message is a bit different."
"When using the ``--verbosity`` option, one must also specify some value, any "
"The above example accepts arbitrary integer values for ``--verbosity``, but "
"for our simple program, only two values are actually useful, ``True`` or "
"``False``. Let's modify the code accordingly::"
"The option is now more of a flag than something that requires a value. We "
"even changed the name of the option to match that idea. Note that we now "
"specify a new keyword, ``action``, and give it the value ``\"store_true\"``. "
"This means that, if the option is specified, assign the value ``True`` to :"
"data:`args.verbose`. Not specifying it implies ``False``."
"It complains when you specify a value, in true spirit of what flags actually "
msgid "Notice the different help text."
msgid "Short options"
"If you are familiar with command line usage, you will notice that I haven't "
"yet touched on the topic of short versions of the options. It's quite "
msgid "And here goes:"
msgid "Note that the new ability is also reflected in the help text."
msgid "Combining Positional and Optional arguments"
msgid "Our program keeps growing in complexity::"
msgid "And now the output:"
msgid "We've brought back a positional argument, hence the complaint."
msgid "Note that the order does not matter."
"How about we give this program of ours back the ability to have multiple "
"verbosity values, and actually get to use them::"
"These all look good except the last one, which exposes a bug in our program. "
"Let's fix it by restricting the values the ``--verbosity`` option can "
"Note that the change also reflects both in the error message as well as the "
"help string."
"Now, let's use a different approach of playing with verbosity, which is "
"pretty common. It also matches the way the CPython executable handles its "
"own verbosity argument (check the output of ``python --help``)::"
"We have introduced another action, \"count\", to count the number of "
"occurrences of a specific optional arguments:"
"Yes, it's now more of a flag (similar to ``action=\"store_true\"``) in the "
"previous version of our script. That should explain the complaint."
msgid "It also behaves similar to \"store_true\" action."
"Now here's a demonstration of what the \"count\" action gives. You've "
"probably seen this sort of usage before."
"And if you don't specify the ``-v`` flag, that flag is considered to have "
"``None`` value."
"As should be expected, specifying the long form of the flag, we should get "
"the same output."
"Sadly, our help output isn't very informative on the new ability our script "
"has acquired, but that can always be fixed by improving the documentation "
"for our script (e.g. via the ``help`` keyword argument)."
msgid "That last output exposes a bug in our program."
msgid "Let's fix::"
msgid "And this is what it gives:"
"First output went well, and fixes the bug we had before. That is, we want "
"any value >= 2 to be as verbose as possible."
msgid "Third output not so good."
msgid "Let's fix that bug::"
"We've just introduced yet another keyword, ``default``. We've set it to "
"``0`` in order to make it comparable to the other int values. Remember that "
"by default, if an optional argument isn't specified, it gets the ``None`` "
"value, and that cannot be compared to an int value (hence the :exc:"
"`TypeError` exception)."
msgid "And:"
"You can go quite far just with what we've learned so far, and we have only "
"scratched the surface. The :mod:`argparse` module is very powerful, and "
"we'll explore a bit more of it before we end this tutorial."
msgid "Getting a little more advanced"
"What if we wanted to expand our tiny program to perform other powers, not "
"just squares::"
msgid "Output:"
"Notice that so far we've been using verbosity level to *change* the text "
"that gets displayed. The following example instead uses verbosity level to "
"display *more* text instead::"
msgid "Conflicting options"
"So far, we have been working with two methods of an :class:`argparse."
"ArgumentParser` instance. Let's introduce a third one, :meth:"
"`add_mutually_exclusive_group`. It allows for us to specify options that "
"conflict with each other. Let's also change the rest of the program so that "
"the new functionality makes more sense: we'll introduce the ``--quiet`` "
"option, which will be the opposite of the ``--verbose`` one::"
"Our program is now simpler, and we've lost some functionality for the sake "
"of demonstration. Anyways, here's the output:"
"That should be easy to follow. I've added that last output so you can see "
"the sort of flexibility you get, i.e. mixing long form options with short "
"form ones."
"Before we conclude, you probably want to tell your users the main purpose of "
"your program, just in case they don't know::"
"Note that slight difference in the usage text. Note the ``[-v | -q]``, which "
"tells us that we can either use ``-v`` or ``-q``, but not both at the same "
msgid "Conclusion"
"The :mod:`argparse` module offers a lot more than shown here. Its docs are "
"quite detailed and thorough, and full of examples. Having gone through this "
"tutorial, you should easily digest them without feeling overwhelmed."
Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

FilesExpand file tree

argparse.po

Latest commit

History

argparse.po

File metadata and controls
