For/Else Loop

Python

Today I encounter python snippet code and something take my attention. And the concept is similar to below code.

for i in range(7):
     print("for")
     if i == 10:
          print("if")
          break
else:
     print("else")

for i in range(7):

print("for")

if i == 10:

print("if")

break

else:

print("else")

Output:
for
for
for
for
for
for
for
else

Output:

for

else

And I recognize else statement is not given an error. After some research, I found the miracle, for/else loop. The concept of this loop is when for is finished without break else statement run if break else statement is passed. Bellow code is an example of usage.

for n in range(2, 10):
    for x in range(2, n):
        if n % x == 0:
            print( n, 'equals', x, '*', n/x)
            break
    else:
        # loop fell through without finding a factor
        print(n, 'is a prime number')

for n in range(2, 10):

for x in range(2, n):

if n % x == 0:

print( n, 'equals', x, '*', n/x)

break

else:

# loop fell through without finding a factor

print(n, 'is a prime number')

Output:
2 is a prime number
3 is a prime number
4 equals 2 * 2.0
5 is a prime number
6 equals 2 * 3.0
7 is a prime number
8 equals 2 * 4.0
9 equals 3 * 3.0

Output:

2 is a prime number

3 is a prime number

4 equals 2 * 2.0

5 is a prime number

6 equals 2 * 3.0

7 is a prime number

8 equals 2 * 4.0

9 equals 3 * 3.0

This tip is can be helpful you can check for loops in for loops it can be more efficient in some cases

For/Else Loop

Python

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