SyntaxError: f-string expression part cannot include a backslash

SyntaxError: f-string expression part cannot include a backslash #

The Python "SyntaxError: f-string expression part cannot include a backslash" occurs when we use a backslash between the curly braces of a formatted string. To solve the error, store the backslash character in a variable or move it out of the curly braces of the f-string.

Here is an example of how the error occurs.

Copied!
first = 'James'
last = 'Doe'

# ⛔️ SyntaxError: f-string expression part cannot include a backslash
result = f'{first\n}{last}'

We can't use a backslash in the expression part (the curly braces) of a formatted string literal.

One way to solve the error is to extract the \ or the \n character in a variable.

Copied!
first = 'James'
last = 'Doe'

nl_char = '\n' * 2

result = f'{first}{nl_char}{last}'

# James

# Doe
print(result)

If your use case doesn't require an expression, and all you have is a backslash or a \n char, move it out of the curly braces.

Copied!
first = 'James'
last = 'Doe'

result = f'{first}\n{last}'

# James
# Doe
print(result)

Here is another example of extracting a newline char in a variable, so we can use it in the expression of an f-string.

Copied!
employees = ['Alice', 'Bob', 'Carl']

newline_char = '\n'

my_str = f'Employees list: \n{newline_char.join(employees)}'

# Employees list:
# Alice
# Bob
# Carl
print(my_str)

Formatted string literals (f-strings) let us include expressions inside of a string by prefixing the string with f.

Copied!
my_str = 'is subscribed:'

my_bool = True

result = f'{my_str} {my_bool}'

print(result)  # 👉️ is subscribed: True

Make sure to wrap expressions in curly braces - {expression}.

Conclusion #

The Python "SyntaxError: f-string expression part cannot include a backslash" occurs when we use a backslash between the curly braces of a formatted string. To solve the error, store the backslash character in a variable or move it out of the curly braces of the f-string.