Python for loop paired with else traps

Suppose you have the following code:

 for  in range:    if i = = 5        :print'found it! i =%s ' % ielse:    print'notfound it ... '

The result you expect is that when found 5 o'clock print out:

Found it! i = 5

The results are actually printed as:

Found it! i = 5 not found it ...

Obviously this is not the result we expect.

According to the official documentation:

>when the items are exhausted (which isImmediately when the sequence isEmpty), the suiteinchTheElseClauseifPresent isExecuted andThe loop terminates.>a BreakStatement executedinchThe first suite terminates the loop without executing theElseClause ' s suite. AContinueStatement executedinchThe first suite skips the rest of the suite andContinues with the next item,orWith theElseClauseifthere was no next Item.https:Docs.python.org/2/reference/compound_stmts.html#the-for-statement

The main idea is that when an iteration of an object is iterated and empty, the clause at else is executed, and if a break is included in the For loop, the loop is terminated, and the ELSE clause is not executed.

So the correct wording should be:

 for  in range:    if i = = 5:        print'found it! i =%s  ' % i        breakElse:    print' not found it ... '

When you use Pylint to detect code, you are prompted

 break statement (useless-else-on-loop)

So it is necessary to develop the habit of using Pylint to detect code, and it is difficult to notice such logic errors.

MMM ~

Reprinted from: https://www.cnblogs.com/dspace/p/6622799.html

Python for loop paired with else traps