Data Science Wizardry Blog by Attila Vajda

zip() takes as its input iterables.

Is insight type iterable?

The following is a scrambled line of Python one liner:

sum([range(1, 6) zip(5, 0, -1)] a, b for a*b in) if

Some of the elements in this scrambled code are:

sum(), range(1,6), zip(), a*b, if, in

After reading the puzzle, the question "What is the noteworthiness of zip(5, 0, -1)?" occurred to me.

Even though the line is scrambled, the meaning of zip() remains a mystery to me.

>>> zip()
<zip object at 0x10d595100>

Since unraveling the mysteries of zip() is required to assemble the pieces of this jigsaw puzzle, we embark on a journey to do so.

>>> zip(0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable

While poking at the function might return errors, the results can serve as valuable insight into the workings of zip(). Unless we read the error message, we cannot adjust the code for a desired result. zip() takes an iterable input, but 0 is 'int' . Is 0 'int', or isn't int iterable?

>>> zip({1,2,3})
<zip object at 0x10d595240>

The set { x | x ∈ {1, 2, 3} } is iterable, because it can be given to zip() as its input.

for, in and [] suggest a list comprehension zip() will take an iterable, range() is iterable

>>> zip([a*b for a if b in range(0,6,-1)]
  File "<stdin>", line 1
    zip([a*b for a if b in range(0,6,-1)]
                                        ^
SyntaxError: invalid syntax
>>> [*zip([a for a in range(0,6)])]
[(0,), (1,), (2,), (3,), (4,), (5,)]

Whenever an a value is generated in the range(0,6), it is enclosed in parentheses and given a comma as a companion. Since inputing the iterable [0, 1, 2, 3, 4, 5] into zip() results as above, we can infer that zip() puts parentheses around elements and appends them with a comma. Perhaps it creates tuples of elements.

I am stuck, so I will try to add sum() to the line.

>>> sum(zip([a for a in range(0,6)]))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'tuple'

Before adding int to tuple, sum() returns an error.

>>> [*zip([sum([(a * b) for a in range(6)]) for b in range(5) if 0-1])]
[(0,), (15,), (30,), (45,), (60,)]

This is a solution I came up with that uses all of the provided elements.

Wow! I asked the computer agent for the intended solution, and it is a cool one liner:

>>> sum([a * b for a, b in zip(range(1, 6), range(5, 0, -1))])
35