This is a fundamental SyntaxError that means you got your variables and your values backwards. When you encounter SyntaxError cannot assign to literal, it usually means you are trying to assign a value to a number or string instead of a variable.

• “Literal”: A “literal” is a raw, fixed value in your code, like the number 5 or the string "hello".
• “Assign”: This refers to the equals sign (=), which is the assignment operator.

It means: “You are trying to assign a new value to a raw value, which is impossible.”

# WRONG — value on the left, variable on the right: assignment is backwards
5 = x               # SyntaxError: cannot assign to literal
"hello" = message   # SyntaxError: cannot assign to literal

# WRONG — single = inside an if statement: assignment instead of comparison
x = 10
if x = 5:           # SyntaxError: cannot assign to literal
    print("x is 5")

# RIGHT — variable name on the left, value on the right
x = 5               # x gets the value 5
message = "hello"   # message gets the string

# RIGHT — == for comparison inside if statements, = only for assignment
if x == 5:          # == compares, = assigns — these are two different operators
    print("x is 5")

The Cause

The rule of assignment in Python is: variable_name = value

You have written value = variable_name.

Problem Code:

# You are trying to assign 'x' to '5'
5 = x
# CRASH! SyntaxError: cannot assign to literal

Python is reading this as “I need to make the number 5 mean whatever x is,” which is not allowed.

The Fix

Simply flip the statement so the variable name is on the left.

x = 5 # Correct!

Common Related Error: Confusing = with ==

This error also pops up if you use a single equals (=) in an if statement by mistake.

Problem Code:

if x = 5: # This is ASSIGNMENT
    print("x is 5")
# CRASH! SyntaxError: invalid syntax (or 'cannot assign to literal')

The Fix: Use the double-equals (==) for comparison.

if x == 5: # This is COMPARISON
    print("x is 5")

SyntaxError: cannot assign to literal — The Assignment Rule and the = vs == Mistake That Trips Every Beginner

SyntaxError: cannot assign to literal fires before Python runs a single line. The parser reads left to right — finds a raw number or string on the left side of =, has nowhere to store the value, and stops immediately.

The assignment rule has no exceptions: the left side of = must be a name, the right side must be a value. 5 = x attempts to make the number 5 hold whatever x is — Python has no mechanism for that. x = 5 stores the value 5 in a container named x — that’s valid everywhere.

Three literal types fire this error on the left side of =:

Integer literals: 5 = x, 100 = total
String literals: “hello” = greeting, “Alice” = name
Float literals: 3.14 = pi

All three follow the same fix: flip the statement. x = 5, greeting = “hello”, pi = 3.14.

The = vs == confusion produces the same error class in a different context. Inside an if, while, or any conditional expression, = means assignment and == means comparison. Python 3 fires SyntaxError: cannot assign to literal when it sees if x = 5: because the parser interprets it as an attempt to assign 5 to the expression result — an impossible target.

= assigns. == compares. := is the walrus operator — it assigns and returns the value in one expression for use inside conditions. These three operators look similar and do completely different things.

All three in context

x = 10 # = assigns: x now holds 10
if x == 10: print(“match”) # == compares: True when x is 10
if (n := len(“hello”)) > 3: # := assigns and evaluates in one step
print(f”Long string: {n}”) # Output: Long string: 5