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SyntaxError: invalid syntax. Maybe you meant '==' or ':=' instead of '='?

What it means

You used a single = where Python expected a condition. One = stores a value in a variable. Two, ==, asks whether two values are equal, which is what an if, elif or while needs.

1. Using `=` to compare in an `if`

This raises the error

Broken
password = "python123"
if password = "python123":
print("Access granted")
Output
Traceback (most recent call last):
  File "<exec>", line 2
    if password = "python123":
       ^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: invalid syntax. Maybe you meant '==' or ':=' instead of '='?

The fix

Fixed
password = "python123"
if password == "python123":
print("Access granted")
Output
Access granted

== compares the two sides and gives True or False, which is what an if needs to decide.

Try fixing it yourself in the editor

2. One `=` in an `elif` after a correct `if`

This raises the error

Broken
day = "Sat"
if day == "Mon":
print("Back to work")
elif day = "Sat":
print("Weekend!")
Output
Traceback (most recent call last):
  File "<exec>", line 4
    elif day = "Sat":
         ^^^^^^^^^^^
SyntaxError: invalid syntax. Maybe you meant '==' or ':=' instead of '='?

The fix

Fixed
day = "Sat"
if day == "Mon":
print("Back to work")
elif day == "Sat":
print("Weekend!")
Output
Weekend!

Every condition needs its own ==. A program can be right in one branch and wrong in the next.

Try fixing it yourself in the editor

3. Trying to store a value inside the condition

This raises the error

Broken
words = ["hi", "hello", "hey"]
if n = len(words):
print(n, "words")
Output
Traceback (most recent call last):
  File "<exec>", line 2
    if n = len(words):
       ^^^^^^^^^^^^^^
SyntaxError: invalid syntax. Maybe you meant '==' or ':=' instead of '='?

The fix

Fixed
words = ["hi", "hello", "hey"]
if (n := len(words)) > 2:
print(n, "words")
Output
3 words

To store a value and test it in one go, Python uses the walrus operator :=. A plain n = len(words) on the line before the if is just as good and easier to read.

Try fixing it yourself in the editor

When you see this error, check

  • In if, elif and while conditions, compare with ==.
  • Use != for not equal, and <= or >= for less or greater than or equal.
  • Keep a single = for lines that store a value, like name = "Ada".
  • Inside a list comprehension, [n for n in nums if n % 2 = 0] gives a plain invalid syntax, but the fix is the same ==.

Related errors

All Python errors · How to read a traceback · Step through your code