#Python's keyword arguments in functions

When calling a function, arguments can be passed either by position or by name, for example:

# Define function
def attack(attack_power: float, defense_power: float):
    # Calculate damage
    damage: float = attack_power * (1 - defense_power / (defense_power + 100))
    print(f"Dealt {damage} points of damage")

# Positional arguments
attack(100, 10)

# Keyword arguments - order does not matter
attack(defense_power=10, attack_power=100)
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Arguments passed by name like this are called keyword arguments.

Keyword arguments must appear at the end of the argument list during a call; otherwise, ambiguity arises. For example, this is invalid:

# Define function
def attack(attack_power: float, defense_power: float):
    damage: float = attack_power * (1 - defense_power / (defense_power + 100))
    print(f"Dealt {damage} points of damage")

# This will cause an error: after keyword argument defense_power=10, 
# it's unclear what 100 refers to (positional or keyword)
attack(defense_power=10, 100)
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#Positional-Only and Keyword-Only Parameters

You can use / and * in the function parameter list to enforce argument passing rules:

• Parameters before / can only be passed positionally
• Parameters after * can only be passed by keyword
• Parameters between / and * can be passed either way

Example:

def func(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):
    pass
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• pos1 and pos2 must be passed positionally.
• kwd1 and kwd2 must be passed as keyword arguments.
• pos_or_kwd can be passed either way.