If you provide the keyword argument first followed by a positional argument, the Python interpreter will raise SyntaxError: positional argument follows keyword argument.
In this tutorial, we will learn what SyntaxError: positional argument follows keyword argument means and how to resolve this error with examples.
What is SyntaxError: positional argument follows keyword argument?
An argument is a variable, value, or object passed to a method or function as an input. We have two types of arguments in Python, and we can pass these arguments while calling the methods.
Positional Argument -The positional arguments are the one that does not have any keyword in front of them.
Example
result = add_numbers(10, 20, 30)
Keyword Argument -The Keyword arguments are the one that has a keyword in front of them.
Example
result = add_numbers(a=10, b=20, c=30)Every programming language has its own set of rules. These rules are referred to as the syntax that needs to be followed while programming.
The positional and keyword arguments must appear in a specific order; otherwise, the Python interpreter will throw a Syntax error.
The Python rule says positional arguments must appear first, followed by the keyword arguments if we are using it together to call the method.
The SyntaxError: positional argument follows keyword argument means we have failed to follow the rules of Python while writing a code.
Let us take a simple example to demonstrate this error.
# Method that takes 3 arguments and returns sum of it
def add_numbers(a, b, c):
return a+b+c
# call the method by passing the arguments
result = add_numbers(a=10, 20, 30)
# print the output
print("Addition of numbers is", result)
Output
File "c:\Personal\IJS\Code\main.py", line 8
result = add_numbers(a=10, 20, 30)
^
SyntaxError: positional argument follows keyword argumentWe have passed the Keyword argument first in the above code and then followed by the Positional argument which breaks the rule and hence we get the SyntaxError.
How to fix SyntaxError: positional argument follows keyword argument?
There are several ways to fix the error. Let us look at all the correct ways to call the methods in Python.
Scenario 1 – Use only Positional Arguments.
The easier way to fix the issue is to use only Positional arguments while calling the method in Python.
Let us fix our example by passing only positional arguments and see what happens when we run the code.
# Method that takes 3 arguments and returns sum of it
def add_numbers(a, b, c):
return a+b+c
# call the method by passing only positional arguments
result = add_numbers(10, 20, 30)
# print the output
print("Addition of numbers is", result)
Output
Addition of numbers is 60
The code runs without any error as Python knows which values to use for each argument in the function.
Scenario 2 – Use only Keyword Arguments.
Another way to resolve the error is to use only the Keyword arguments while calling the method in Python.
# Method that takes 3 arguments and returns sum of it
def add_numbers(a, b, c):
return a+b+c
# call the method by passing only keyword arguments
result = add_numbers(a=10, b=20, c=30)
# print the output
print("Addition of numbers is", result)
Output
Addition of numbers is 60
The code runs without any error as Python knows which values to use for each argument in the function.
Scenario 3 – Use Positional arguments first, followed by Keyword Arguments.
If you need to use both positional and keyword arguments, you need to abide by the rules of Python.
The Positional arguments should always appear first, followed by the keyword arguments.
In the below example, we have fixed the issue by passing the two positional arguments first and then a keyword argument.
# Method that takes 3 arguments and returns sum of it
def add_numbers(a, b, c):
return a+b+c
# pass all positional arguments first and then keyword arguments
result = add_numbers(10, 20, c=30)
# print the output
print("Addition of numbers is", result)
Output
Addition of numbers is 60
Conclusion
In Python, the SyntaxError: positional argument follows keyword argument occurs if you pass keyword arguments before the positional arguments. Since Python interprets positional arguments in the order in which they appear first and then followed by the keyword arguments as next.
We can resolve the SyntaxError by providing all the positional arguments first, followed by the keyword arguments at last.
Srinivas Ramakrishna
