Write the test in a python docstring

The doctest.testmod () function of the doctest module describes the test in the docstring and runs it in verbose mode to execute the test.

Where I used to write

sample.py

def twice(n):
    """A function that doubles the argument and returns
    >>> twice(8)
    16
    >>> twice(1850923)
    """
    return n * 2


'''TEST
twice(8)
 #Execution result
 #16
twice(1850923)
 #Execution result
 #3701846
'''#← Triple quotes here'TEST'By pulling up to the place where it is written, twice(8), twice(1850923)To run

If you raise the triple quote under TEST to TEST, the docstring-like multi-line comment out will be removed, and when executed, the twice function will be executed and tested. That TEST is below the function, so it looks bad. I want to put it together in a docstring if possible.

Use the doctest module

However, if you use the doctest module, you can write it in the docstring, and you can do dexterity that does not execute when executed from other modules.

doctest_sample.py

def twice(n):
    """A function that doubles the argument and returns
    >>> twice(8)
    16
    >>> twice(1850923)
    3701846
    """
    return n * 2


print('name?>>', __name__)
if __name__ == "__main__":
    doctest.testmod()

print('EOF')

Verify the execution result by the following four methods

1. ipython
   1. %run doctest_sample -v
   2. %run doctest_use.py -v
2. sublimetext
3. Run doctest_sample.py on sublime text
4. Run doctest_use.py.py on sublime text

Just import the contents of doctest_use.py.py

import doctest_sample
```

When running a python file on ipython, run it with'% run '. When using doctest.testmod (), execute it in verbose mode -v.

When executing on sublime text, build with ctrl + b. Execution of verbose mode is not included by default (whether it is false or true or not verified), so create a build system and save it in the User directory Select Python_Verbose created from Menu> Tools> Buile system and ctrl + b

Python_Verbose.sublime-build

{
    "cmd": ["python", "$file", "-v"],
    "file_regex": "^[ ]*File \"(...*?)\", line ([0-9]*)",
    "selector": "source.python"
}

About command line options -u and -v

1 Command line and environment (http://docs.python.jp/3.3/using/cmdline.html) 1.1 Command line 1.1.3 Other options

-u¶ (original)

Force the binary layer of the stdout and stderr streams (which is available as their buffer attribute) to be unbuffered. The text I/O layer will still be line-buffered if writing to the console, or block-buffered if redirected to a non-interactive file.

See also PYTHONUNBUFFERED.

-v

Each time a module is initialized, it displays a message telling you where it was loaded (filename or built-in module). If specified twice (-vv), a message will be displayed for each file checked when searching for modules. It also provides information about module cleanup on exit. See also PYTHONVERBOSE.

Result 1.1 % run doctest_sample -v on ipython

1.1

In [80]: run doctest_sample.py -v
name?>> __main__
Trying:
    twice(8)
Expecting:
    16
ok
Trying:
    twice(1850923)
Expecting:
    3701846
ok
1 items had no tests:
    __main__
1 items passed all tests:
   2 tests in __main__.twice
2 tests in 2 items.
2 passed and 0 failed.
Test passed.
EOF

Since the name attribute is main, doctest is executed The description of doctest is Execute in python format where you wrote > >> and return the result If there are no errors, issue ʻok` and proceed to the next test.

1.1

Trying:
    twice(8)
Expecting:
    16
ok

View test summary

1.1

1 items had no tests:
    __main__
1 items passed all tests:
   2 tests in __main__.twice
2 tests in 2 items.
2 passed and 0 failed.
Test passed.
body...

Result 1.2 % run doctest_use -v on ipython

1.2

In [81]: run doctest_use.py

No output is displayed.

Result 2.1 Build doctest_sample.py on sublime text

2.1

name?>> __main__
Trying:
    twice(8)
Expecting:
    16
ok
Trying:
    twice(1850923)
Expecting:
    3701846
ok
1 items had no tests:
    __main__
1 items passed all tests:
   2 tests in __main__.twice
2 tests in 2 items.
2 passed and 0 failed.
Test passed.
EOF
[Finished in 0.5s]

Same as 1.1 result except [Finished in 0.5s] that appears in sublime text build result

Result 2.2 Build doctest_use.py on sublime text

2.2

name?>> doctest_sample
EOF
[Finished in 0.4s]

Unlike result 1.2, the print statement seems to be executed.

Summary

• Write the test in the docstring
• Write docstring.testmod ()
• Put it in the if statement so that it will be executed when the name attribute is main (see doc.py)
• Run python in verbose mode (python <filename> -v)

doc.py

import docstring

def hoge():
    '''
    hoge(args)
    '''


if __name__ == "__main__":
    doctest.testmod()

reference

Test with Python Command line and environment