MenttesLabs

9.1. Doctest

Factorial

"""
This is the "factorial" module.

The example module supplies one function, factorial().  For example,

"""

def factorial(n):
    """Return the factorial of n, an exact integer >= 0.
    If the result is small enough to fit in an int, return an int.
    Else return a long.
    """

    import math
    if not n >= 0:
        raise ValueError("n must be >= 0")
    if math.floor(n) != n:
        raise ValueError("n must be exact integer")
    if n+1 == n:  # catch a value like 1e300
        raise OverflowError("n too large")
    result = 1
    factor = 2
    while factor <= n:
        result *= factor
        factor += 1
    return result

>>> from factorial import factorial
>>> factorial(1)
1
>>> factorial(2)
2
>>> factorial(3)
6
>>> factorial(4)
24
>>> factorial(-1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "factorial.py", line 46, in factorial
    raise ValueError("n must be >= 0")
ValueError: n must be >= 0
>>> factorial(-2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "factorial.py", line 46, in factorial
    raise ValueError("n must be >= 0")
ValueError: n must be >= 0
>>> from sys import maxint
>>> factorial(maxint*maxint)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "factorial.py", line 48, in factorial
    raise ValueError("n must be exact integer")
ValueError: n must be exact integer
>>> maxint*maxint
4611686014132420609L

"""
This is the "example" module.

The example module supplies one function, factorial().  For example,

>>> factorial(5)
120
"""

def factorial(n):
    """Return the factorial of n, an exact integer >= 0.

    If the result is small enough to fit in an int, return an int.
    Else return a long.

    >>> [factorial(n) for n in range(6)]
    [1, 1, 2, 6, 24, 120]
    >>> [factorial(long(n)) for n in range(6)]
    [1, 1, 2, 6, 24, 120]
    >>> factorial(30)
    265252859812191058636308480000000L
    >>> factorial(30L)
    265252859812191058636308480000000L
    >>> factorial(-1)
    Traceback (most recent call last):
        ...
    ValueError: n must be >= 0

    Factorials of floats are OK, but the float must be an exact integer:
    >>> factorial(30.1)
    Traceback (most recent call last):
        ...
    ValueError: n must be exact integer
    >>> factorial(30.0)
    265252859812191058636308480000000L

    It must also not be ridiculously large:
    >>> factorial(1e100)
    Traceback (most recent call last):
        ...
    OverflowError: n too large
    """

    import math
    if not n >= 0:
        raise ValueError("n must be >= 0")
    if math.floor(n) != n:
        raise ValueError("n must be exact integer")
    if n+1 == n:  # catch a value like 1e300
        raise OverflowError("n too large")
    result = 1
    factor = 2
    while factor <= n:
        result *= factor
        factor += 1
    return result

def _test():
    import doctest
    doctest.testmod()

if __name__ == "__main__":
    _test()

$ python factorial.py 
$

Editando:

    while factor <= n:
        result *= factor

por

    while factor <= n:
        result += factor

resulta

$ python factorial.py 
**********************************************************************
File "factorial.py", line 6, in __main__
Failed example:
    factorial(5)
Expected:
    120
Got:
    15
**********************************************************************
File "factorial.py", line 16, in __main__.factorial
Failed example:
    [factorial(n) for n in range(6)]
Expected:
    [1, 1, 2, 6, 24, 120]
Got:
    [1, 1, 3, 6, 10, 15]
**********************************************************************
File "factorial.py", line 18, in __main__.factorial
Failed example:
    [factorial(long(n)) for n in range(6)]
Expected:
    [1, 1, 2, 6, 24, 120]
Got:
    [1, 1, 3, 6, 10, 15]
**********************************************************************
File "factorial.py", line 20, in __main__.factorial
Failed example:
    factorial(30)
Expected:
    265252859812191058636308480000000L
Got:
    465
**********************************************************************
File "factorial.py", line 22, in __main__.factorial
Failed example:
    factorial(30L)
Expected:
    265252859812191058636308480000000L
Got:
    465
**********************************************************************
File "factorial.py", line 34, in __main__.factorial
Failed example:
    factorial(30.0)
Expected:
    265252859812191058636308480000000L
Got:
    465
**********************************************************************
2 items had failures:
   1 of   1 in __main__
   5 of   8 in __main__.factorial
***Test Failed*** 6 failures.

Unit testing

"""
Este modulo imprime cuantos dias fatlan para un evento que ocurre el 12/08/2008

El modulo provee una sola funcion, cuantosDias().  For example,

"""

from datetime import *

def cuantosDias():
    """Devuelve cuantos dias faltan para las jornadas
  
    >>> type( cuantosDias() )
    <type 'int'>
    """
    today = date.today()
    evento = date(2008, 8, 12)
    dias = evento - today
    
    return(dias.days)
    

def _test():
    import doctest
    doctest.testmod()

if __name__ == "__main__":
    _test()

"""
Este modulo prueba jrsl con unit test
"""
from jrsl import *
import unittest

class Test(unittest.TestCase):
    def test_dias(self):
        self.assertEquals( cuantosDias(), 89 )

    def test_tipo(self):
        self.assertEquals( type(cuantosDias()) , int)
                 
if __name__ == '__main__':
    unittest.main()                

Ejercicio