asExpert Examples

Creates an alias (used with import, with, except)

as bytecode across contexts

How 'as' compiles in different uses.

python
import dis

def import_as():
    import json as j
    return j

def except_as():
    try:
        pass
    except ValueError as e:
        return e

def with_as():
    class CM:
        def __enter__(self): return 1
        def __exit__(self, *a): pass
    with CM() as val:
        return val

print("import as:")
dis.dis(import_as)
print("\nexcept as:")
dis.dis(except_as)
print("\nwith as:")
dis.dis(with_as)

# import as: IMPORT_NAME + STORE_FAST (stores under alias name)
# except as: STORE_FAST + DELETE_FAST after block
# with as: STORE_FAST (stores __enter__ return value)

'as' is not a single bytecode operation — it's syntactic sugar. Import as renames the stored name. Except as stores then deletes the exception. With as stores the __enter__ return value.

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