¿Puedes poner un bucle if en un bucle if?

Can you put an if loop in an if loop?

No, you can’t. The if condition must evaluate to some boolean value, which doesn’t happen with this for loop.

Tips

1. The break statement exits a for or while loop completely. To skip the rest of the instructions in the loop and begin the next iteration, use a continue statement.
2. break is not defined outside a for or while loop. To exit a function, use return .

In most of the programming languages (C/C++, Java, etc), the use of else statement has been restricted with the if conditional statements. But Python also allows us to use the else condition with for loops. The else block just after for/while is executed only when the loop is NOT terminated by a break statement.

Semicolon is a legitimate statement called null statement * that means “do nothing”. Since the for loop executes a single operation (which could be a block enclosed in {} ) semicolon is treated as the body of the loop, resulting in the behavior that you observed.

Generally you want to restrict the scope of your objects as much as possible. If your variable is only used inside the loop, and you do not require state to carry between iterations, then yes you usually want to declare it inside the loop so that each iteration contains a fresh variable. Sometimes this carries performance penalties, as you suggest.

The iteration variable steps successively through the three strings stored in the friends variable. Often we use a for or while loop to go through a list of items or the contents of a file and we are looking for something such as the largest or smallest value of the data we scan through. These loops are generally constructed by:

The body of the loop should change the value of one or more variables so that eventually the condition becomes false and the loop terminates. We call the variable that changes each time the loop executes and controls when the loop finishes the iteration variable.

For the above loop, we would say, “It had five iterations”, which means that the body of the loop was executed five times. The body of the loop should change the value of one or more variables so that eventually the condition becomes false and the loop terminates.