Breaking Down Python's Built in Function `zip`

ZIP

zip() is more efficient in both memory usage and simplicity, and it's preferred for combining objects in Python, especially when working with multiple iterables.

Key points about zip():

• It combines multiple iterables (such as lists, tuples, or strings) element by element.
• It returns an iterator of tuples, where each tuple contains one element from each of the input iterables.
• The function stops when the shortest iterable is exhausted, so if the input lists are of different lengths, the result will be truncated to match the shortest list.

Example:

a = [1, 2, 3]
b = ['a', 'b', 'c']
zipped = zip(a, b)
print(list(zipped))

Output:

[(1, 'a'), (2, 'b'), (3, 'c')]

In the case below, zip() is used to combine elements from the names and primary_types lists.

names = ['User1', 'User2', 'User3', 'User4', 'User5']
primary_types = ['Electric', 'Fire', 'Flood']

# Combine the first five items from names and the first three from primary_types
differing_lengths = [*zip(names[:5], primary_types[:3])]

# Print the result
print(*differing_lengths, sep='\n')

Step-by-step Breakdown

1. List Declaration

names = ['User1', 'User2', 'User3', 'User4', 'User5']
primary_types = ['Electric', 'Fire', 'Flood']

• Two lists are declared:
  • names contains five user names: ['User1', 'User2', 'User3', 'User4', 'User5'].
  • primary_types contains three types: ['Electric', 'Fire', 'Flood'].

2. Slicing Lists:

names[:5]   # ['User1', 'User2', 'User3', 'User4', 'User5']
primary_types[:3]  # ['Electric', 'Fire', 'Flood']

• names[:5] retrieves the first five elements of the names list (in this case, all elements).
• primary_types[:3] retrieves the first three elements of the primary_types list.

3. Using zip:

zip(names[:5], primary_types[:3])

• The zip() function pairs up elements from both lists based on the shortest list's length.
• Since primary_types has only 3 elements, only the first 3 items from names are zipped:('User1', 'Electric')('User2', 'Fire')('User3', 'Flood')
• The resulting pairs are returned as tuples in a zip object.

4. Unpacking and Creating a List:

differing_lengths = [*zip(names[:5], primary_types[:3])]

• The [*zip(...)] syntax unpacks the zip object and turns it into a list of tuples.
• The result will be:

[('User1', 'Electric'), ('User2', 'Fire'), ('User3', 'Flood')]

5. Printing the Result:

python print(*differing_lengths, sep='\n')

• print(*differing_lengths) unpacks the list, printing each tuple separately.
• sep='\n' ensures that each tuple is printed on a new line.
• The output will be

  ('User1', 'Electric')
  ('User2', 'Fire')
  ('User3', 'Flood')

Summary

This code takes two lists (names and primary_types), combines the first five names and the first three primary types using zip(), and prints each pair of items from the two lists line by line.