A for loop in Python is a control flow statement that allows you to iterate over a sequence of values, such as a list, tuple, or string, and perform a set of instructions for each element of the sequence.
The basic syntax of a for loop in Python is as follows:
for element in sequence: # do something with element
element is a variable that represents the current element of the sequence being processed, and
sequence is the sequence of values being iterated over. The
: character is used to indicate the start of a new block of code, which is executed for each element of the sequence.
Let’s look at an example that demonstrates how to use a for loop to iterate over a list of numbers and print each element:
numbers = [1, 2, 3, 4, 5] for num in numbers: print(num)
1 2 3 4 5
In this example,
numbers is a list of integers, and the
for loop iterates over each element in the list and assigns it to the variable
print() function is then called to output the value of
num to the console.
You can also use the
range() function with a for loop to iterate over a range of numbers. For example:
# Example 1 for i in range(5): print(i) # Output: 0 1 2 3 4 # Example 2 for i in range(1, 10, 2): print(i) # Output: 1 3 5 7 9
In the first example,
range(5) generates a sequence of numbers starting from 0 and ending at 4 (not including 5), and the for loop iterates over this sequence and prints each number.
In the second example,
range(1, 10, 2) generates a sequence of odd numbers starting from 1 and ending at 9 (not including 10), and the for loop iterates over this sequence and prints each number.