traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

#14034: fix indentation.

This commit is contained in:
Ezio Melotti 2012-05-06 17:05:16 +03:00
parent 6cc7a41c2f
commit 9ab3fdd8cb
1 changed files with 78 additions and 78 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

156
Doc/howto/argparse.rst
View File

@ -84,7 +84,7 @@ Following is a result of running the code:
usage: prog.py [-h]
optional arguments:
-h, --help show this help message and exit
-h, --help show this help message and exit
$ python3 prog.py --verbose
usage: prog.py [-h]
prog.py: error: unrecognized arguments: --verbose
@ -128,10 +128,10 @@ And running the code:
usage: prog.py [-h] echo
positional arguments:
echo
echo
optional arguments:
-h, --help show this help message and exit
-h, --help show this help message and exit
$ python3 prog.py foo
foo
@ -170,10 +170,10 @@ And we get:
usage: prog.py [-h] echo
positional arguments:
echo echo the string you use here
echo echo the string you use here
optional arguments:
-h, --help show this help message and exit
-h, --help show this help message and exit
Now, how about doing something even more useful::
@ -181,7 +181,7 @@ Now, how about doing something even more useful::
parser = argparse.ArgumentParser()
parser.add_argument("square", help="display a square of a given number")
args = parser.parse_args()
print(args.square**2))
print(args.square**2)
Following is a result of running the code:
@ -189,8 +189,8 @@ Following is a result of running the code:
$ python3 prog.py 4
Traceback (most recent call last):
File "prog.py", line 5, in <module>
print(args.square**2)
File "prog.py", line 5, in <module>
print(args.square**2)
TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int'
That didn't go so well. That's because :mod:`argparse` treats the options we
@ -200,7 +200,7 @@ give it as strings, unless we tell it otherwise. So, let's tell
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", help="display a square of a given number",
type=int)
type=int)
args = parser.parse_args()
print(args.square**2)
@ -229,7 +229,7 @@ have a look on how to add optional ones::
parser.add_argument("--verbosity", help="increase output verbosity")
args = parser.parse_args()
if args.verbosity:
print("verbosity turned on")
print("verbosity turned on")
And the output:
@ -242,8 +242,8 @@ And the output:
usage: prog.py [-h] [--verbosity VERBOSITY]
optional arguments:
-h, --help show this help message and exit
--verbosity VERBOSITY
-h, --help show this help message and exit
--verbosity VERBOSITY
increase output verbosity
$ python3 prog.py --verbosity
usage: prog.py [-h] [--verbosity VERBOSITY]
@ -272,10 +272,10 @@ Let's modify the code accordingly::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("--verbose", help="increase output verbosity",
action="store_true")
action="store_true")
args = parser.parse_args()
if args.verbose:
print("verbosity turned on")
print("verbosity turned on")
And the output:
@ -283,15 +283,15 @@ And the output:
$ python3 prog.py --verbose
verbosity turned on
$ python3 prog.py --verbose 1
$ python3 prog.py --verbose 1
usage: prog.py [-h] [--verbose]
prog.py: error: unrecognized arguments: 1
$ python3 prog.py --help
usage: prog.py [-h] [--verbose]
optional arguments:
-h, --help show this help message and exit
--verbose increase output verbosity
-h, --help show this help message and exit
--verbose increase output verbosity
Here is what is happening:
@ -318,10 +318,10 @@ versions of the options. It's quite simple::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("-v", "--verbose", help="increase output verbosity",
action="store_true")
action="store_true")
args = parser.parse_args()
if args.verbose:
print("verbosity turned on")
print("verbosity turned on")
And here goes:
@ -333,8 +333,8 @@ And here goes:
usage: prog.py [-h] [-v]
optional arguments:
-h, --help show this help message and exit
-v, --verbose increase output verbosity
-h, --help show this help message and exit
-v, --verbose increase output verbosity
Note that the new ability is also reflected in the help text.
@ -347,15 +347,15 @@ Our program keeps growing in complexity::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display a square of a given number")
help="display a square of a given number")
parser.add_argument("-v", "--verbose", action="store_true",
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbose:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
else:
print(answer)
print(answer)
And now the output:
@ -381,17 +381,17 @@ multiple verbosity values, and actually get to use them::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display a square of a given number")
help="display a square of a given number")
parser.add_argument("-v", "--verbosity", type=int,
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbosity == 2:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
elif args.verbosity == 1:
print("{}^2 == {}".format(args.square, answer))
print("{}^2 == {}".format(args.square, answer))
else:
print(answer)
print(answer)
And the output:
@ -415,17 +415,17 @@ Let's fix it by restricting the values the ``--verbosity`` option can accept::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display a square of a given number")
help="display a square of a given number")
parser.add_argument("-v", "--verbosity", type=int, choices=[0, 1, 2],
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbosity == 2:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
elif args.verbosity == 1:
print("{}^2 == {}".format(args.square, answer))
print("{}^2 == {}".format(args.square, answer))
else:
print(answer)
print(answer)
And the output:
@ -438,11 +438,11 @@ And the output:
usage: prog.py [-h] [-v {0,1,2}] square
positional arguments:
square display a square of a given number
square display a square of a given number
optional arguments:
-h, --help show this help message and exit
-v {0,1,2}, --verbosity {0,1,2}
-h, --help show this help message and exit
-v {0,1,2}, --verbosity {0,1,2}
increase output verbosity
Note that the change also reflects both in the error message as well as the
@ -455,17 +455,17 @@ verbosity argument (check the output of ``python --help``)::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display the square of a given number")
help="display the square of a given number")
parser.add_argument("-v", "--verbosity", action="count",
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbosity == 2:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
elif args.verbosity == 1:
print("{}^2 == {}".format(args.square, answer))
print("{}^2 == {}".format(args.square, answer))
else:
print(answer)
print(answer)
We have introduced another action, "count",
to count the number of occurences of a specific optional arguments:
@ -487,11 +487,11 @@ to count the number of occurences of a specific optional arguments:
usage: prog.py [-h] [-v] square
positional arguments:
square display a square of a given number
square display a square of a given number
optional arguments:
-h, --help show this help message and exit
-v, --verbosity increase output verbosity
-h, --help show this help message and exit
-v, --verbosity increase output verbosity
$ python3 prog.py 4 -vvv
16
@ -521,19 +521,19 @@ Let's fix::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display a square of a given number")
help="display a square of a given number")
parser.add_argument("-v", "--verbosity", action="count",
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
# bugfix: replace == with >=
if args.verbosity >= 2:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
elif args.verbosity >= 1:
print("{}^2 == {}".format(args.square, answer))
print("{}^2 == {}".format(args.square, answer))
else:
print(answer)
print(answer)
And this is what it gives:
@ -545,8 +545,8 @@ And this is what it gives:
the square of 4 equals 16
$ python3 prog.py 4
Traceback (most recent call last):
File "prog.py", line 11, in <module>
if args.verbosity >= 2:
File "prog.py", line 11, in <module>
if args.verbosity >= 2:
TypeError: unorderable types: NoneType() >= int()
* First output went well, and fixes the bug we had before.
@ -559,17 +559,17 @@ Let's fix that bug::
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("square", type=int,
help="display a square of a given number")
help="display a square of a given number")
parser.add_argument("-v", "--verbosity", action="count", default=0,
help="increase output verbosity")
help="increase output verbosity")
args = parser.parse_args()
answer = args.square**2
if args.verbosity >= 2:
print("the square of {} equals {}".format(args.square, answer))
print("the square of {} equals {}".format(args.square, answer))
elif args.verbosity >= 1:
print("{}^2 == {}".format(args.square, answer))
print("{}^2 == {}".format(args.square, answer))
else:
print(answer)
print(answer)
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.
@ -605,11 +605,11 @@ not just squares::
args = parser.parse_args()
answer = args.x**args.y
if args.verbosity >= 2:
print("{} to the power {} equals {}".format(args.x, args.y, answer))
print("{} to the power {} equals {}".format(args.x, args.y, answer))
elif args.verbosity >= 1:
print("{}^{} == {}".format(args.x, args.y, answer))
print("{}^{} == {}".format(args.x, args.y, answer))
else:
print(answer)
print(answer)
Output:
@ -622,12 +622,12 @@ Output:
usage: prog.py [-h] [-v] x y
positional arguments:
x the base
y the exponent
x the base
y the exponent
optional arguments:
-h, --help show this help message and exit
-v, --verbosity
-h, --help show this help message and exit
-v, --verbosity
$ python3 prog.py 4 2 -v
4^2 == 16
@ -644,9 +644,9 @@ to display *more* text instead::
args = parser.parse_args()
answer = args.x**args.y
if args.verbosity >= 2:
print("Running '{}'".format(__file__))
print("Running '{}'".format(__file__))
if args.verbosity >= 1:
print("{}^{} == ".format(args.x, args.y), end="")
print("{}^{} == ".format(args.x, args.y), end="")
print(answer)
Output:
@ -685,11 +685,11 @@ which will be the opposite of the ``--verbose`` one::
answer = args.x**args.y
if args.quiet:
print(answer)
print(answer)
elif args.verbose:
print("{} to the power {} equals {}".format(args.x, args.y, answer))
print("{} to the power {} equals {}".format(args.x, args.y, answer))
else:
print("{}^{} == {}".format(args.x, args.y, answer))
print("{}^{} == {}".format(args.x, args.y, answer))
Our program is now simpler, and we've lost some functionality for the sake of
demonstration. Anyways, here's the output:
@ -728,11 +728,11 @@ your program, just in case they don't know::
answer = args.x**args.y
if args.quiet:
print(answer)
print(answer)
elif args.verbose:
print("{} to the power {} equals {}".format(args.x, args.y, answer))
print("{} to the power {} equals {}".format(args.x, args.y, answer))
else:
print("{}^{} == {}".format(args.x, args.y, answer))
print("{}^{} == {}".format(args.x, args.y, answer))
Note that slight difference in the usage text. Note the ``[-v | -q]``,
which tells us that we can either use ``-v`` or ``-q``,
@ -746,13 +746,13 @@ but not both at the same time:
calculate X to the power of Y
positional arguments:
x the base
y the exponent
x the base
y the exponent
optional arguments:
-h, --help show this help message and exit
-v, --verbose
-q, --quiet
-h, --help show this help message and exit
-v, --verbose
-q, --quiet
Conclusion