Python Exponentiation

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Arithmetic Exponentiation

# Basic syntax
result = 2 ** 3  # Evaluates to 8


# Right-associativity
chain = 2 ** 3 ** 2  # Evaluates to 512 (2 ** 9), not 64 (8 ** 2)


# Precedence with unary operators
neg_a = -3 ** 2   # Evaluates to -9. Parsed as -(3 ** 2)
neg_b = (-3) ** 2 # Evaluates to 9. Parsed as (-3) ** 2

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Mapping Unpacking and Packing

• Dictionary Displays: Expands the key-value pairs into a new dictionary literal. If duplicate keys exist, the values from the rightmost unpacked mapping overwrite previous values.
• Function Invocations: Expands the mapping into discrete keyword arguments. The keys must be strings. These string keys must match the function’s explicitly defined parameter names, unless the function signature includes a **kwargs catch-all parameter, in which case any valid string key is accepted. This unpacking is evaluated dynamically at runtime; the compiler emits a bytecode instruction (such as CALL_FUNCTION_EX) to handle the expansion during execution.
• Function Signatures: When used in a function definition (def func(**kwargs):), it acts as a packing parameter, capturing all unbound keyword arguments into a single dictionary bound to the specified identifier.

# Dictionary display unpacking
map1 = {'a': 1, 'b': 2}
map2 = {'b': 3, 'c': 4}
combined = {**map1, **map2}  # Evaluates to {'a': 1, 'b': 3, 'c': 4}


# Function invocation unpacking
def target_function(a, b):
    pass

args = {'a': 10, 'b': 20}
target_function(**args)  # Evaluated dynamically at runtime via CALL_FUNCTION_EX


# Function signature packing
def capture_kwargs(**kwargs):
    # kwargs is bound to a dictionary of passed keyword arguments
    pass