In Python, the *
symbol has several different uses depending on the context in which it is used. Here are some of the common uses of the *
symbol in Python:
- Multiplication Operator:
You can use the*
symbol as the multiplication operator to multiply numbers or variables together. For example:
result = 5 * 3 # This will assign the value 15 to the variable 'result'.
- Exponentiation Operator:
Python uses**
for exponentiation. For example:
result = 2 ** 3 # This will assign the value 8 to the variable 'result' (2 raised to the power of 3).
- Asterisk in Function Definitions and Function Calls:
The*
symbol can be used in function definitions and function calls to deal with variable-length argument lists. When used in a function definition,*args
is used to collect all positional arguments into a tuple. When used in a function call,*
is used to unpack a list or tuple into separate positional arguments. For example:
def add(*args):
total = 0
for num in args:
total += num
return total
result = add(1, 2, 3, 4) # This will assign the value 10 to 'result'.
- Argument Unpacking:
You can use the*
symbol to unpack elements from an iterable like a list or tuple into individual items. For example:
numbers = [1, 2, 3, 4]
a, b, *rest = numbers
print(a) # 1
print(b) # 2
print(rest) # [3, 4]
- Repetition Operator:
The*
symbol can be used for string repetition and list repetition. For example:
text = "Hello, " * 3 # This will create the string "Hello, Hello, Hello, "
numbers = [0] * 5 # This will create a list with five 0s: [0, 0, 0, 0, 0]
- Keyword Argument Unpacking:
In Python 3, you can use**
to unpack keyword arguments from a dictionary into a function call. For example:
def greet(name, age):
print(f"Hello, {name}! You are {age} years old.")
person_info = {"name": "Alice", "age": 30}
greet(**person_info) # This will call the greet function with keyword arguments.
These are some of the common uses of the *
symbol in Python. Its exact behavior depends on the context in which it is used.