Python if, elif, and else Statements

Learn how Python if, elif, and else statements choose one branch from multiple alternatives, with menu, range, input validation, and troubleshooting examples.

A conditional statement runs code depending on whether a condition is true or false. Python uses if, elif, and else to choose between possible paths.

An if/else decision has two possible paths: the if path runs when its condition is true, and the else path runs otherwise. An if/elif/else chain can choose among three or more alternatives. Common uses include menus, category selection, input validation, and status messages.

In a conditional chain, each possible path is called a branch. A condition is an expression that produces a Boolean value: either True or False.

Python if, elif, and else Syntax

The general structure contains one initial if clause, zero or more elif clauses, and an optional final else clause:

if condition:
    statements
elif another_condition:
    statements
else:
    statements

if is the first conditional clause and is always checked first.
elif means “else if.” It adds another condition to the same decision chain.
else is an optional fallback branch. It has no condition.
Every condition is followed by a colon, :.
Statements belonging to a branch must be indented. Four spaces is the usual style.

elif is Python syntax for an additional branch; it is not a standalone condition statement. It must follow an if or another elif in the same chain.

A small example

temperature = 22

if temperature < 10:
    print("It is cold.")
elif temperature < 25:
    print("It is mild.")
else:
    print("It is warm.")

The indented print() statements are the blocks controlled by their corresponding clauses. Related branches should remain at the same indentation level.

Clause Roles

Clause — Condition required — When evaluated — When its block runs

if — Yes — First — When its condition is true.

elif — Yes — In order, after earlier conditions are false — When its condition is true and no earlier branch matched.

else — No — Last — When every preceding if and elif condition is false.

Evaluation Order and Branch Selection

Python evaluates conditions from top to bottom. It executes the first branch whose condition is true. After that branch runs, Python skips every later elif and the else branch.

score = 85

if score >= 90:
    print("A")
elif score >= 80:
    print("B")
elif score >= 70:
    print("C")
else:
    print("Below C")

Here, score >= 90 is false, so Python checks score >= 80. That condition is true, so it prints B and does not check the remaining branches.

The else branch runs only when every preceding condition is false. It is useful as a fallback for unmatched cases.

Order overlapping conditions carefully

When conditions overlap, put the most specific or highest threshold first. Otherwise, a broad condition may capture a value before a later branch can examine it.

score = 95

# Correct: the higher threshold comes first.
if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
elif score >= 70:
    grade = "C"
else:
    grade = "Needs improvement"

print(grade)

If score >= 70 appeared first, a score of 95 would match that condition and incorrectly receive C.

Conditions and Comparison Operators

Each if or elif condition must evaluate to a Boolean value. Comparison operators create Boolean results by comparing values.

Operator — Meaning — Example — Example result

== — Equal to — choice == 2 — True when choice is 2.

!= — Not equal to — status != "done" — True when status is not "done".

< — Less than — age < 18 — True when age is below 18.

<= — Less than or equal to — temperature <= 0 — True when temperature is 0 or lower.

> — Greater than — balance > 0 — True when balance is positive.

>= — Greater than or equal to — score >= 50 — True when score is at least 50.

Use == to compare values. Use = to assign a value to a variable:

choice = 2          # Assignment

if choice == 2:     # Comparison
    print("Option 2 selected.")

Using = where a comparison is needed causes a syntax error. For a broader review of these operators, see Python comparison operators.

Interactive Numbered Menu

This example displays five vehicle choices, reads the user's selection, converts the text to an integer, and selects one response.

print("Choose a vehicle:")
print("1. Bicycle")
print("2. Bus")
print("3. Car")
print("4. Train")
print("5. Boat")

selection = int(input("Choose an option: "))

if selection == 1:
    print("You selected a bicycle.")
elif selection == 2:
    print("You selected a bus.")
elif selection == 3:
    print("You selected a car.")
elif selection == 4:
    print("You selected a train.")
elif selection == 5:
    print("You selected a boat.")
else:
    print("That is not a supported vehicle choice.")

input() always reads user input as text. int() converts suitable text such as "2" into the integer 2, allowing numeric comparisons.

Example output

Choose a vehicle:
1. Bicycle
2. Bus
3. Car
4. Train
5. Boat
Choose an option: 2
You selected a bus.

If the user enters 0 or 6, conversion succeeds, but no listed comparison is true. The else branch then displays the invalid-selection message.

Invalid Numeric and Non-numeric Input

There are two different invalid-input cases:

An unlisted numeric choice, such as 0 or 6, reaches the conditional chain and is handled by else.
Non-numeric text, such as two, cannot be converted by int(). Python raises ValueError before it reaches the conditional chain.

User entry — Conversion result — Conditional outcome — Displayed response

A valid listed number — An integer, such as 2 — Its matching branch runs — The selected vehicle message.

An unlisted number — An integer, such as 0 — No condition matches, so else runs — The unsupported-choice message.

Non-numeric text — Conversion raises ValueError — The chain is not reached — Use try/except to display an input error.

Safe numeric conversion

Wrap the conversion in try/except when users may enter arbitrary text:

try:
    selection = int(input("Choose an option: "))
except ValueError:
    print("Enter a whole number.")
else:
    if selection == 1:
        print("You selected a bicycle.")
    elif selection == 2:
        print("You selected a bus.")
    elif selection == 3:
        print("You selected a car.")
    elif selection == 4:
        print("You selected a train.")
    elif selection == 5:
        print("You selected a boat.")
    else:
        print("That is not a supported vehicle choice.")

The except ValueError block handles text that is not a whole number. Valid integers continue to the menu decision. You can learn more about exception handling in Python try/except statements.

Choosing elif or Separate if Statements

Use an if/elif/else chain when the outcomes are mutually exclusive: only one response should run.

points = 75

if points >= 90:
    print("Excellent")
elif points >= 60:
    print("Passing")
else:
    print("Try again")

Use separate if statements when more than one action may need to run. Separate statements continue evaluating after a previous condition is true.

temperature = 30

if temperature > 20:
    print("Wear light clothing.")
if temperature > 25:
    print("Drink extra water.")

Both messages can appear because these are two independent decisions. Replacing the second if with elif would make the branches mutually exclusive.

More Range-Checking Examples

Letter grade classification

score = 88

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
elif score >= 70:
    grade = "C"
elif score >= 60:
    grade = "D"
else:
    grade = "F"

print("Grade:", grade)

Temperature advice

temperature = 28

if temperature < 10:
    print("It is cold.")
elif temperature < 20:
    print("It is mild.")
elif temperature < 30:
    print("It is warm.")
else:
    print("It is hot.")

These ranges are ordered from lower to higher values. Once a temperature matches one range, later ranges are skipped.

Readability and Maintainability

Use descriptive conditions and output messages that explain the result.
Order overlapping conditions from the most specific or highest threshold to the broader cases.
Keep every branch at the same indentation level within a chain.
Use else when an unmatched case needs a clear fallback.
Keep the chain manageable. An excessively long elif sequence may be clearer as a dictionary lookup, a function, a match statement, or another data-driven structure.

The foundational if/elif/else structure is still the right starting point for understanding conditional branching. See the Python if statement for a single condition and Python if/else statements for two-way decisions.

Running and Troubleshooting Your Code

Save a menu example in a file such as filename.py, then run it from a terminal with:

python filename.py

Common problems

Using = instead of ==: assignment is being used where equality comparison is required. Write if selection == 2:.
IndentationError or code outside the intended branch: branch statements are not consistently indented. Indent each statement in a branch, typically by four spaces.
A later elif never runs: an earlier condition is too broad or already matches the same values. Review top-to-bottom evaluation and reorder the conditions.
else does not handle text such as two: int() fails before the chain is reached. Use try/except ValueError, or compare text choices directly.
More than one response appears: separate if statements were used even though only one outcome should be selected. Use an if/elif/else chain.
else causes a syntax error: check that it has a trailing colon, is aligned with its if and elif clauses, and belongs to an existing conditional chain.

Exam-relevant note: Remember the three rules: conditions are checked from top to bottom, only the first true branch in an if/elif chain runs, and else runs only when all preceding conditions are false.

Key Points

if starts a conditional decision.
elif adds one or more alternative conditions.
else is an optional, condition-free fallback.
Colons and indentation define the structure of each branch.
Use == for comparison and = for assignment.
Use a chain for mutually exclusive outcomes and separate if statements when multiple actions may run.
Handle non-numeric input around int() with try/except ValueError.