PythonHow-ToBeginner · 3 min read

How to Use For Loop in Python: Syntax and Examples

In Python, a for loop is used to repeat a block of code for each item in a sequence like a list or string. You write it as for variable in sequence: followed by an indented block of code to run for each item.

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Syntax

The for loop syntax in Python is simple and easy to read. It starts with the keyword for, followed by a variable name that will hold each item from the sequence one by one. Then comes the keyword in, followed by the sequence (like a list, string, or range). The loop body is indented and contains the code to repeat.

for: starts the loop
variable: temporary name for each item
in: keyword to check membership
sequence: the collection to loop over
:: marks the start of the loop block
indented block: code to run each time

python

for item in sequence:
    # code to run for each item

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Example

This example shows a for loop that prints each fruit in a list. It demonstrates how the loop variable takes each value and runs the print statement for each one.

python

fruits = ['apple', 'banana', 'cherry']
for fruit in fruits:
    print(fruit)

Output

apple banana cherry

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Common Pitfalls

One common mistake is forgetting the colon : after the for statement, which causes a syntax error. Another is not indenting the loop body properly, which leads to indentation errors. Also, modifying the sequence inside the loop can cause unexpected behavior.

python

wrong:
for i in range(3):
print(i)

right:
for i in range(3):
    print(i)

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Quick Reference

Part	Description
for	Starts the loop
variable	Holds current item from sequence
in	Checks membership in sequence
sequence	List, string, range, or other iterable
:	Marks start of loop block
Indented block	Code to repeat for each item

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Key Takeaways

Use for variable in sequence: to loop over items in Python.

Indent the loop body to tell Python what to repeat.

Remember the colon : after the for statement.

Avoid changing the sequence inside the loop to prevent bugs.

Use range() to loop a specific number of times.