How does zip() work in Python?
What is zip()?
The zip() method in python returns a zip object by taking in iterables, like lists or strings, and aggregating them into tuples.
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No parameter: When given no iterable as a parameter,
zip()returns an empty iterator. -
Single parameter: When given a single iterable argument,
zip()returns an iterator of tuples with each tuple only having one element. -
Multiple parameters: When given multiple iterables,
zip()returns an iterator of tuples with each tuple having multiple elements.
serialNumbers = [1, 2, 3]names = ['Sarah', 'John', 'Harry']# No iterables are passedresult = zip()print(result)# With a single iterableresult = zip(serialNumbers)print(result)# With multiple iterablesresult = zip(serialNumbers, names)print(result)
Purpose
The purpose of this function is to map the elements of iterables to the same indexes in the tuples.
serialNumbers = [1, 2, 3]names = ['Sarah', 'John', 'Harry']result = zip(serialNumbers, names)print(result)# Now, to get a clear picture of how zip()# function is mapping both the iterables:for a,b in zip(serialNumbers, names):print(a,b)
Reading the result
In order to obtain the output in a readable format, you can use tuple() to view the result in the form of tuples. You may also use list() or set() functions, as seen below:
serialNumbers = [1, 2, 3]names = ['Sarah', 'John', 'Harry']result = zip(serialNumbers, names)# Use tuple() function to read the resultprint(tuple(result))# Converting itertor to listresultList = list(result)print(resultList)# Converting to setresultSet = set(result)print(resultSet)
What happens with input iterables of different lengths?
The iterator returned form zip() stops when one of the input iterable is exhausted.
serialNumbers = [1, 2, 3, 4, 5] # length = 5names = ['Sarah', 'John', 'Harry'] # length = 3for a,b in zip(serialNumbers, names):print(a,b)
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