def __pow__(self, exponent):
'''Raise the perm by the power of `exponent`.'''
assert isinstance(exponent, numbers.Integral)
if exponent <= -1:
return self.inverse**(-exponent)
elif exponent == 0:
return self.nominal_perm_space[0]
else:
assert exponent >= 1
return misc_tools.general_product((self, ) * exponent)
def __pow__(self, exponent):
'''Raise the perm by the power of `exponent`.'''
assert isinstance(exponent, numbers.Integral)
if exponent <= -1:
return self.inverse ** (- exponent)
elif exponent == 0:
return self.nominal_perm_space[0]
else:
assert exponent >= 1
return misc_tools.general_product((self,) * exponent)
def factorial(x, start=1):
'''
Calculate a factorial.
This differs from the built-in `math.factorial` in that it allows a `start`
argument. If one is given, the function returns `(x!)/(start!)`.
Examples:
>>> factorial(5)
120
>>> factorial(5, 3)
60
'''
from combi._python_toolbox import misc_tools
return misc_tools.general_product(xrange(start, x + 1), start=1)
def factorial(x, start=1):
'''
Calculate a factorial.
This differs from the built-in `math.factorial` in that it allows a `start`
argument. If one is given, the function returns `(x!)/(start!)`.
Examples:
>>> factorial(5)
120
>>> factorial(5, 3)
60
'''
from combi._python_toolbox import misc_tools
return misc_tools.general_product(xrange(start, x+1), start=1)
def product(numbers):
'''Get the product of all the numbers in `numbers`.'''
from combi._python_toolbox import misc_tools
return misc_tools.general_product(numbers, start=1)
def product(numbers):
'''Get the product of all the numbers in `numbers`.'''
from combi._python_toolbox import misc_tools
return misc_tools.general_product(numbers, start=1)