Python For Loop

The for loop is a control structure in Python that allows you to iterate over a sequence of elements such as a list, tuple, string, or range. It is used when you want to perform a set of instructions for each element in the sequence. Let's explore the syntax and usage of the for loop in Python with examples.

Syntax

The basic syntax of a for loop in Python is as follows:

    for item in sequence:
    # Code to execute for each item in the sequence
  

Example 1: Printing Numbers

Consider the following example:

    numbers = [1, 2, 3, 4, 5]

for num in numbers:
    print(num)
  

In this example, we have a list of numbers. The for loop iterates over each element in the list and assigns it to the variable "num". Inside the loop, we print the value of "num". The loop repeats for each number in the list, resulting in the numbers being printed one by one.

Example 2: Summing Numbers

You can also use a for loop to perform calculations. Here's an example that calculates the sum of numbers from 1 to 10:

    sum = 0

for num in range(1, 11):
    sum += num

print("The sum is:", sum)
  

In this example, we use the range() function to generate a sequence of numbers from 1 to 10 (excluding 11). The for loop iterates over each number in the range and adds it to the variable "sum". After the loop terminates, we print the final value of "sum," which is the sum of numbers from 1 to 10.

Example 3: Iterating Over Strings

The for loop can also iterate over characters in a string. Here's an example:

    message = "Hello, World!"

for char in message:
    print(char)
  

In this example, the for loop iterates over each character in the string "message" and assigns it to the variable "char". Inside the loop, we print each character, resulting in the string being printed character by character.

Conclusion

The for loop is a versatile construct in Python that allows you to iterate over sequences and perform operations on each element. By understanding the syntax and usage of the for loop, you can efficiently process data, perform calculations, and manipulate strings in your Python programs.