Python for Loop

Python for loop is basically used to execute a sequence of code multiple times.

Python for Loop Syntax

Here is the general form to use for loop in python:

for iterating-var in sequence:
	statement(s)

Here, if the sequence contains an expression list, then it is evaluated first. And the first item in the sequence is assigned to the iterating variable, that is, iterating-var. Next, the statement(s) block is executed. Here, each item in the list is assigned to the iterating-var, and the statement(s) block is executed until the entire sequence is completed or exhausted.

Python for Loop Example

Here is an example program, illustrates the concept and use of for loop in python:

# Python for Loop - Example Program

for letter in 'python':
    print("The current letter is ", letter);

Here is the sample run of the above python program:

Here is another program, also demonstrates the use of python for loop. This program uses the range() function to return a list of consecutive integers. The range() function can have one, two, or three parameters/arguments. The range() function must have at least one parameters.

# Python for Loop - Example Program

for val in range(10):
    print(val)

Here is the output produced by the above python program:

Here is one more example, also illustrates for loop in python:

# Python for Loop - Example Program

for val in range(10, 20):
    print(val)

Below is the output of the above python program:

Python for Loop - Count Forward

Counting forward using python for loop can easily be done as shown in the following example code.

Below example of for loop will count the number upto the range of 10, that is, from 0 to 9.

# Python for Loop Example - Count forward using for loop
print("Welcome to Python for loop example program.");
print("This example count the number in forward direction.");
print("Counting...");
for num in range(10):
    print(num);

Here is the sample output produced by the above for loop example.

Python for Loop - Count Backward

You can also count the number in backward direction using python for loop as shown in the example given below.

This for loop example code will count the number in backward.

# Python for loop - counting backward example
print("Welcome to counting backward example code using Python for loop.");
print("Counting in backward started...");
for num in range(10, 0, -1):
    print(num);

Below is the sample output of above counting backward example using for loop in python.

Python for Loop - Count by Number

You can also count by any number upto to some range using python for loop as shown in the example given below.

This example will count by 10 upto the range of 100, that is from 0 to 90.

# Python for loop example
# Python counting by number example using for loop
print("Welcome to counting by number example using for loop");
print("Started counting by the number, 10...");
for num in range(0, 100, 10):
    print(num);

Below is the output you will see on your output screen, when running the above counting by number example code using python for loop.

More Examples

Here are the list of some more examples on python for loop:

Python Online Test

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