For Loop in Python

In Python, the for loop is used to iterate over a sequence (such as a list, tuple, string, or range) or any iterable object. Here's the basic syntax of a For loop in Python:

pythonCopy codefor item in iterable:
    # Code block to execute for each iteration
    # You can use the 'item' variable to access the current element
    # of the iterable

Here's a breakdown of how it works:

  • item: This is a variable name that represents the current element in the iteration. You can choose any valid variable name here.

  • iterable: This is the object over which the loop iterates. It could be a list, tuple, string, dictionary, or any other iterable object.

  • Indentation: In Python, indentation is crucial for defining blocks of code. The code block following the for statement is indented, typically by four spaces (or a tab), to indicate that it belongs to the loop.

Example 1: Iterating over a list:

pythonCopy codefruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

Output:

apple
banana
cherry

Example 2: Iterating over a string:

pythonCopy codefor char in "hello":
    print(char)

Output:

h
e
l
l
o

Example 3: Using range() for a numerical loop:

pythonCopy codefor i in range(5):
    print(i)

Output:

0
1
2
3
4

In this last example, range(5) generates numbers from 0 to 4, and the loop iterates over these numbers, assigning each to the variable i.

Remember, the for loop can be used with any iterable object in Python, making it a versatile tool for iteration. Learn more with programs such as masters in data Science and free python tutorial online!