Pattern: Too many positional arguments
Issue: -
Used when a function has too many positional arguments.
Example of incorrect code:
# +1: [too-many-positional-arguments]
def calculate_drag_force(velocity, area, density, drag_coefficient):
"""Each argument is positional-or-keyword unless a `/` or `*` is present."""
return 0.5 * drag_coefficient * density * area * velocity**2
drag_force = calculate_drag_force(30, 2.5, 1.225, 0.47)Example of correct code:
def calculate_drag_force(*, velocity, area, density, drag_coefficient):
"""This function is 'Keyword only' for all args due to the '*'."""
return 0.5 * drag_coefficient * density * area * velocity**2
# This is now impossible to do and will raise a TypeError:
# drag_force = calculate_drag_force(30, 2.5, 1.225, 0.47)
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
# TypeError: calculate_drag_force() takes 0 positional arguments but 4 were given
# And this is the only way to call 'calculate_drag_force'
drag_force = calculate_drag_force(
velocity=30, area=2.5, density=1.225, drag_coefficient=0.47
)