Python Zip function- How to combine multiple iterable sequences?

---

In the computer, zipping files means combining multiple files into a single one. The zip() function in Python combines multiple iterable objects (strings, lists, etc.) into a single object. It returns a new iterable sequence in which each element at an index is the union of elements at the same index from each input sequence.

How does the zip() function work?

• In the zip function, one or more iterable objects are passed as arguments and return a list of tuples. Where individual tuple contains one element from each object passed into the function.
• If no argument is passed, it returns an empty list (no tuples).
• If a single argument is passed, the function converts the object to a list of tuples where each element is a tuple with a single element.
  

Syntax ->

retVal = zip(* iterables) or zip(iterable1, iterable2, ...iterableN);

Description->

Arguments (iterables) – These can be one or more built-in iterable (string, list, etc.) or be user-defined.
Value Returned(retVal) – Return a list of tuples.

---

How to use the zip function in a Python program?

The following is the primary example of how two lists of the same size will be zipped.

# Program to combine two lists 
list_1 = [100,200];
list_2 = ["century", "double century"];

outcome = zip(list_1,list_2);

print(list(outcome));

[(100, 'century'), (200, 'double century')]

How to zip multiple sequences of different sizes?

We are passing three lists of different sizes in the following example. The output will consist of a list with the number of items equal to the smallest iterable passed in.

# Program to combine three lists of different sizes
list_1 = [100,200, 0];
list_2 = ["century", "double century", "no runs"];

list_3 = ["Player1", "Player2", "Player3", "Player4"];

outcome = zip(list_1,list_2,list_3);

print(list(outcome));

[(100, 'century', 'Player1'), (200, 'double century', 'Player2'), (0, 'no runs', 'Player3')]

How to get iterable sequences back from a zipped Object?

The process is unzipping a zipped object. The zip() function is used with the * operator and a zipped object. Please note that if the zip is created from sequences of different sizes, the unzip will not produce the original sequences. It will be a lossy unzip.

Unzipping with no loss: Following is an example where the input zipped list was created using sequences having the same number of elements.

# Program to zip three lists of same sizes
list_1 = [100,200, 0];
list_2 = ["century", "double century", "no runs"];

list_3 = ["Player1", "Player2", "Player3"];
#zip 
outcome = zip(list_1,list_2,list_3);
#unzip 
x,y,z = zip(*outcome);

print(x);
print(y);
print(z);

(100, 200, 0)
('century', 'double century', 'no runs')
('Player1', 'Player2', 'Player3')

Unzipping with loss: Following is an example where the input zipped list was created using sequences having a different number of elements.

# Program to zip three lists of different sizes
list_1 = [100,200, 0];
list_2 = ["century", "double century", "no runs"];

list_3 = ["Player1", "Player2", "Player3", "Player4"];
#zip 
outcome = zip(list_1,list_2,list_3);
#unzip 
x,y,z = zip(*outcome);

print(x);
print(y);
print(z);

(100, 200, 0)
('century', 'double century', 'no runs')
('Player1', 'Player2', 'Player3')

When to use zip?

There can be multiple scenarios for using the inbuilt zip function. You can use zip to create a tuple as an element. We can use the zip function to create a dictionary from the lists of keys and values. Or you can use it in for loop to iterate multiple sequences.