When a function is called, it accepts only one value per parameter. Python interpreters will raise a SyntaxError when they see something like
myfunction(a=1, a=2)
, but there are other cases which will only fail at runtime:
- An argument is provided by value and position at the same time.
- Some arguments are provided via unpacking and the same argument is provided twice.
This rule raises an issue when a function is called with multiple values for the same parameter.
Noncompliant Code Example
def func(a, b, c):
return a * b * c
func(6, 93, 31, c=62) # Noncompliant: argument "c" is duplicated
params = {'c':31}
func(6, 93, 31, **params) # Noncompliant: argument "c" is duplicated
func(6, 93, c=62, **params) # Noncompliant: argument "c" is duplicated
Compliant Solution
def func(a, b, c):
return a * b * c
print(func(c=31, b=93, a=6)) # Compliant