itertools in Python (9)

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*Memo:

• My post explains itertools.

product() can return the iterator which does cartesian product with the elements of *iterables one by one to return a tuple of zero or more elements one by one as shown below:

*Memo:

• The 1st arguments are *iterables(Optional-Default:()-Type:Iterable):
  • Don't use any keywords like *iterables=, iterables=, etc.
• The 2nd argument is repeat(Optional-Default:1-Type:int):
  • It's the length of the returned tuple.
  • It must be 0 <= x.
  • repeat= must be used.

from itertools import product

v = product()
v = product((), repeat=0)

print(v)
# <itertools.product object at 0x000001BE99723500>

print(next(v)) # ()
print(next(v)) # StopIteration:

from itertools import product

v = product('ABC')
v = product(['A', 'B', 'C'])

print(next(v)) # ('A',)
print(next(v)) # ('B',)
print(next(v)) # ('C',)
print(next(v)) # StopIteration:

from itertools import product

for x in product('ABC', repeat=2):
# for x in product(['A', 'B', 'C'], repeat=2):
    print(x)
# ('A', 'A')
# ('A', 'B')
# ('A', 'C')
# ('B', 'A')
# ('B', 'B')
# ('B', 'C')
# ('C', 'A')
# ('C', 'B')
# ('C', 'C')

from itertools import product

for x in product('ABC', repeat=3):
# for x in product(['A', 'B', 'C'], repeat=3):
    print(x)
# ('A', 'A', 'A')
# ('A', 'A', 'B')
# ('A', 'A', 'C')
# ('A', 'B', 'A')
# ('A', 'B', 'B')
# ('A', 'B', 'C')
# ('A', 'C', 'A')
# ('A', 'C', 'B')
# ('A', 'C', 'C')
# ('B', 'A', 'A')
# ('B', 'A', 'B')
# ('B', 'A', 'C')
# ('B', 'B', 'A')
# ('B', 'B', 'B')
# ('B', 'B', 'C')
# ('B', 'C', 'A')
# ('B', 'C', 'B')
# ('B', 'C', 'C')
# ('C', 'A', 'A')
# ('C', 'A', 'B')
# ('C', 'A', 'C')
# ('C', 'B', 'A')
# ('C', 'B', 'B')
# ('C', 'B', 'C')
# ('C', 'C', 'A')
# ('C', 'C', 'B')
# ('C', 'C', 'C')

from itertools import product

for x in product('ABC', repeat=4):
# for x in product(['A', 'B', 'C'], repeat=4):
    print(x)
# ('A', 'A', 'A', 'A')
# ('A', 'A', 'A', 'B')
# ('A', 'A', 'A', 'C')
# ('A', 'A', 'B', 'A')
# ('A', 'A', 'B', 'B')
# ('A', 'A', 'B', 'C')
# ('A', 'A', 'C', 'A')
# ('A', 'A', 'C', 'B')
# ('A', 'A', 'C', 'C')
# ('A', 'B', 'A', 'A')
# ('A', 'B', 'A', 'B')
# ('A', 'B', 'A', 'C')
# ('A', 'B', 'B', 'A')
# ('A', 'B', 'B', 'B')
# ('A', 'B', 'B', 'C')
# ('A', 'B', 'C', 'A')
# ('A', 'B', 'C', 'B')
# ('A', 'B', 'C', 'C')
# ('A', 'C', 'A', 'A')
# ('A', 'C', 'A', 'B')
# ('A', 'C', 'A', 'C')
# ('A', 'C', 'B', 'A')
# ('A', 'C', 'B', 'B')
# ('A', 'C', 'B', 'C')
# ('A', 'C', 'C', 'A')
# ('A', 'C', 'C', 'B')
# ('A', 'C', 'C', 'C')
# ('B', 'A', 'A', 'A')
# ('B', 'A', 'A', 'B')
# ('B', 'A', 'A', 'C')
# ...

from itertools import product

for x in product('AB', 'C'):
# for x in product(['A', 'B'], ['C']):
    print(x)
# ('A', 'C')
# ('B', 'C')

from itertools import product

for x in product('AB', 'C', repeat=2):
# for x in product(['A', 'B'], ['C'], repeat=2):
    print(x)
# ('A', 'C', 'A', 'C')
# ('A', 'C', 'B', 'C')
# ('B', 'C', 'A', 'C')
# ('B', 'C', 'B', 'C')

from itertools import product

for x in product('AB', 'C', repeat=3):
# for x in product(['A', 'B'], ['C'], repeat=3):
    print(x)
# ('A', 'C', 'A', 'C', 'A', 'C')
# ('A', 'C', 'A', 'C', 'B', 'C')
# ('A', 'C', 'B', 'C', 'A', 'C')
# ('A', 'C', 'B', 'C', 'B', 'C')
# ('B', 'C', 'A', 'C', 'A', 'C')
# ('B', 'C', 'A', 'C', 'B', 'C')
# ('B', 'C', 'B', 'C', 'A', 'C')
# ('B', 'C', 'B', 'C', 'B', 'C')

from itertools import product

for x in product('AB', 'C', repeat=4):
# for x in product(['A', 'B'], ['C'], repeat=4):
    print(x)
# ('A', 'C', 'A', 'C', 'A', 'C', 'A', 'C')
# ('A', 'C', 'A', 'C', 'A', 'C', 'B', 'C')
# ('A', 'C', 'A', 'C', 'B', 'C', 'A', 'C')
# ('A', 'C', 'A', 'C', 'B', 'C', 'B', 'C')
# ('A', 'C', 'B', 'C', 'A', 'C', 'A', 'C')
# ('A', 'C', 'B', 'C', 'A', 'C', 'B', 'C')
# ('A', 'C', 'B', 'C', 'B', 'C', 'A', 'C')
# ('A', 'C', 'B', 'C', 'B', 'C', 'B', 'C')
# ('B', 'C', 'A', 'C', 'A', 'C', 'A', 'C')
# ('B', 'C', 'A', 'C', 'A', 'C', 'B', 'C')
# ('B', 'C', 'A', 'C', 'B', 'C', 'A', 'C')
# ('B', 'C', 'A', 'C', 'B', 'C', 'B', 'C')
# ('B', 'C', 'B', 'C', 'A', 'C', 'A', 'C')
# ('B', 'C', 'B', 'C', 'A', 'C', 'B', 'C')
# ('B', 'C', 'B', 'C', 'B', 'C', 'A', 'C')
# ('B', 'C', 'B', 'C', 'B', 'C', 'B', 'C')