Python programming language provides following types of loops to handle looping requirements.
while expression: statement(s)
In Python, all the statements indented by the same number of character spaces after a programming construct are considered to be part of a single block of code. Python uses indentation as its method of grouping statements.
Hello Geek Hello Geek Hello Geek
See this for an example where while loop is used for iterators. As mentioned in the article, it is not recommended to use while loop for iterators in python.
In Python, there is no C style for loop, i.e., for (i=0; i<n; i++). There is “for in” loop which is similar to for each loop in other languages.
for iterator_var in sequence: statements(s)
It can be used to iterate over iterators and a range.
List Iteration geeks for geeks Tuple Iteration geeks for geeks String Iteration G e e k s Dictionary Iteration xyz 123 abc 345
We can use for in loop for user defined iterators. See this for example.
Python programming language allows to use one loop inside another loop. Following section shows few examples to illustrate the concept.
for iterator_var in sequence: for iterator_var in sequence: statements(s) statements(s)
The syntax for a nested while loop statement in Python programming language is as follows:
while expression: while expression: statement(s) statement(s)
A final note on loop nesting is that we can put any type of loop inside of any other type of loop. For example a for loop can be inside a while loop or vice versa.
1 2 2 3 3 3 4 4 4 4
Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed. Python supports the following control statements.
It returns the control to the beginning of the loop.
Current Letter : g Current Letter : k Current Letter : f Current Letter : o Current Letter : r Current Letter : g Current Letter : k
It brings control out of the loop
Current Letter : e
We use pass statement to write empty loops. Pass is also used for empty control statement, function and classes.
Last Letter : s
How to print a list in reverse order (from last to first item) using while and for in loops.
This article is contributed by Ashirwad Kumar. If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
- Difference between continue and break statements in C++
- Decision Making in Java (if, if-else, switch, break, continue, jump)
- How to write an empty function in Python - pass statement?
- loops in python
- Output of Python Programs | Set 22 (Loops)
- Break a list into chunks of size N in Python
- Print the pattern by using one loop | Set 2 (Using Continue Statement)
- Maximum students to pass after giving bonus to everybody and not exceeding 100 marks
- Largest of two distinct numbers without using any conditional statements or operators
- Loops in C and C++
- Loops in Java
- Understanding for loops in Java
- Program to find the Break Even Point
- Sum of array Elements without using loops and recursion
- Flow control in try catch finally in Java