Python · Const

else

else supplies a fallback or successful-completion branch in Python compound statements. Its meaning depends on whether it follows if, a loop, or try.

How it works

else is a clause used with conditional statements, loops, and try. Its behavior depends on the construct: it handles the no-match path for if, normal completion for loops without break, and successful completion of a try suite without an exception or early loop-control statement.

Syntax

if_stmt ::= "if" expression ":" suite ("elif" expression ":" suite)* ["else" ":" suite]
while_stmt ::= "while" expression ":" suite ["else" ":" suite]
for_stmt ::= "for" target_list "in" expression_list ":" suite ["else" ":" suite]
try_stmt ::= ("try" ":" suite ("except" [expression ["as" target]] ":" suite)+ ["else" ":" suite] ["finally" ":" suite] | "try" ":" suite ["finally" ":" suite])

Key points

In an if chain, else is the fallback suite when all tested conditions are false.
An if/elif chain executes at most one selected suite.
For a while loop, else runs when the condition becomes false and the loop ends normally.
A try statement's else suite is optional and is considered after control leaves the try suite.
The try else suite requires no exception and no early exit from the try suite.

Common mistakes

An exception raised inside a try statement's else suite is not caught by that statement's preceding except clauses.

Example: Detect whether a loop found a match

for item in [1, 3, 5]:
    if item % 2 == 0:
        print("found")
        break
else:
    print("no even item")

The loop's else suite runs because the loop finishes without executing break.

When to use it

Provide a default path when no `if` or `elif` condition matches.

Conditional branching

Report that a search found nothing when iteration completes without `break`.

Search loops

Run follow-up code only after a `try` suite completes successfully.

Validated operations

Interview questions

QWhen does Python execute an else clause?

In an if statement, else runs only when every preceding condition is false. In a loop, it runs when the loop completes normally: a for loop is exhausted or a while condition becomes false.

Follow-up: How can a loop search use else? Put break in the match branch; the else suite then represents the no-match path because it runs only when no break occurs.

QWhat is special about else on try?

A try else suite runs after the try suite completes without an exception and without return, continue, or break. It is therefore useful for code that should run only after the protected operation succeeds.

Follow-up: Are exceptions in the try else suite caught by the preceding except clauses? No; those handlers apply to the preceding try suite, not to the else suite.

QHow does else work with if and elif?

The if form selects one suite after evaluating conditions in order; if none is true, the else suite runs. Only the selected suite executes, so later branches are not evaluated or executed.

Follow-up: Can an if statement omit else? Yes. The else clause is optional, and with no matching condition no fallback suite executes.

if statement
elif
for statement
while statement
try statement
except clause

Source: 8. Compound statements. Checked 2026-10-16.