How Does Python's `zip()` Function Combine Multiple Lists, and Why Is the Result's Length Unexpected?

Zipping Multiple Lists in Python

In Python, the zip() function allows you to combine multiple lists of equal length into a single list of tuples. Each tuple contains corresponding elements from the original lists.

Unexpected Length of Zipped Result

You encountered an unexpected result when zipping three lists of size 20 into a single list. Instead of obtaining three elements, you received 20. This is because the zip() function creates tuples containing all three elements from each iteration.

Understanding the Result

For example, consider the following lists:

a = [1, 2, 3]
b = [4, 5, 6]
c = [7, 8, 9]

Zipping these lists together would produce the following result:

zip_result = zip(a, b, c)

# Print the length of the zipped result
print(len(zip_result))  # Output: 3

As you can see, the length of the zipped result is 3, even though the original lists have 3 elements each. This is because each element in the zipped result is a tuple containing elements from all three lists:

# Print the first tuple in the zipped result
print(zip_result[0])  # Output: (1, 4, 7)

To determine the number of elements in each tuple, you can examine the length of the first element:

# Get the first tuple in the zipped result
first_tuple = zip_result[0]

# Print the length of the first tuple
print(len(first_tuple))  # Output: 3

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