SyntaxError: cannot assign to function call here in Python

# SyntaxError: cannot assign to function call here (Python)

The Python "SyntaxError: cannot assign to function call here. Maybe you meant '==' instead of '='?" occurs when we try to assign to a function call.

To solve the error, specify the variable name on the left, and the function call on the right-hand side of the assignment.

Here is an example of how the error occurs.

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def get_num():
    return 100


# ⛔️ SyntaxError: cannot assign to function call here. Maybe you meant '==' instead of '='?
get_num() = 'abc'

The error is caused because we are trying to assign a value to a function call.

# Specify the function call on the right-hand side

To solve the error, make sure to specify the function call on the right-hand side of the assignment.

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def get_num():
    return 100

# ✅ Call the function on the right-hand side of the assignment
my_num = get_num()

print(my_num)  # 👉️ 100

Make sure the function returns what you expect because functions that don't explicitly return a value return None.

You can think of a variable as a container that stores a specific value (e.g. the value that the function returns).

The parentheses are used to invoke the function.

If your function takes parameters, make sure to specify them.

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def greet(first, last):
    return 'hello ' + first + ' ' + last


result = greet('bobby', 'hadz')

print(result)  # 👉️ hello bobby hadz

# Use double equals when performing an equality comparison

If you meant to perform an equality comparison, use double equals.

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def get_num():
    return 100

# ✅ Using double equals when comparing values
if 100 == get_num():
    # 👇️ This runs
    print('success')
else:
    print('failure')

We use double equals == for comparison and single equals = for assignment.

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# ✅ Assignment (single equals)
name = 'bobby'

# ✅ Equality comparison (double equals)
if name == 'bobby':
    print('success')

# Use square brackets when adding keys to a Dictionary

You might also get the error when working with a dictionary.

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my_dict = {}

# ⛔️ SyntaxError: cannot assign to function call here. Maybe you meant '==' instead of '='?
my_dict('name') = 'Bobby'

The error is caused because we used parentheses instead of square brackets to add a new key-value pair to the dict.

Make sure to use square brackets if you have to access a key-value pair in a dictionary.

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my_dict = {}

my_dict['name'] = 'Bobby'

print(my_dict['name'])  # 👉️ 'Bobby'

Square brackets are used to add key-value pairs to a dictionary and to access keys in a dictionary.

# Use square brackets when updating or accessing elements in a list

You should also use square brackets when updating or accessing elements in a list.

Here is an example of how the error occurs when parentheses are used.

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my_list = ['bobby', 'hadz', 'com']

# ⛔️ SyntaxError: cannot assign to function call here. Maybe you meant '==' instead of '='?
my_list(0) = 'abc'

To resolve the issue, use square brackets [] instead.

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my_list = ['bobby', 'hadz', 'com']

my_list[0] = 'abc'

print(my_list)  # 👉️ ['abc', 'hadz', 'com']

print(my_list[0])  # 👉️ abc

We used square brackets to update the value of the list element at index 0 and then accessed the element using square brackets.

# Valid names for variables and functions in Python

The name of a variable must start with a letter or an underscore.

A variable name can contain alpha-numeric characters (a-z, A-Z, 0-9) and underscores _.

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def get_num():
    return 100


my_num = get_num()

print(my_num)  # 👉️ 100

Note that variable names cannot start with numbers or be wrapped in quotes.

Variable names in Python are case-sensitive.

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def get_num():
    return 100


def get_num_2():
    return 200


my_num = get_num()
print(my_num)  # 👉️ 100

MY_NUM = get_num_2()
print(MY_NUM)  # 👉️ 200

The 2 variables in the example are completely different and are stored in different locations in memory.

# Incorrect syntax when looping

You might also get the error when you have syntax errors in list comprehensions or generator expressions.

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def get_name():
    return 'bobby'


result = [char for get_name() in char]

# ⛔️ SyntaxError: cannot assign to function call
print(result)

Notice that the order in the list comprehension is incorrect.

Instead, it should be [char for char in get_name()].

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def get_name():
    return 'bobby'


result = [char for char in get_name()]

# ['b', 'o', 'b', 'b', 'y']
print(result)

Make sure the order of operations in your for loops, generator expressions and list comprehensions is correct.

We iterate over the result of calling the function, not over a character or element of the return value of the function.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

• SyntaxError: cannot assign to expression here. Maybe you meant '==' instead of '='?