When a while loop is used inside another while loop then it is called nested while loop in Python. Python allows using one loop inside another loop.
while expression:
while expression:
statement(s)
statement(s)
Example Nested while loop in Python
Simple example code.
i = 1
j = 5
while i < 4:
while j < 8:
print(i, ",", j)
j = j + 1
i = i + 1
Output:

Another example
Display multiplication table using nested while in Python language.
i = 1
while i <= 5:
j = 1
while j <= 5:
print(i, "*", j, '=', i * j)
j += 1
i += 1
print("\n")
Output:
1 * 1 = 1
1 * 2 = 2
1 * 3 = 3
1 * 4 = 4
1 * 5 = 5
2 * 1 = 2
2 * 2 = 4
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
3 * 1 = 3
3 * 2 = 6
3 * 3 = 9
3 * 4 = 12
3 * 5 = 15
4 * 1 = 4
4 * 2 = 8
4 * 3 = 12
4 * 4 = 16
4 * 5 = 20
5 * 1 = 5
5 * 2 = 10
5 * 3 = 15
5 * 4 = 20
5 * 5 = 25
Do comment if you have any doubts and suggestions on this Python While loop program.
Note: IDE: PyCharm 2021.3.3 (Community Edition)
Windows 10
Python 3.10.1
All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.

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