The Python Language Reference, Release 3.9.5 Appendix A. Glossary 118 Arguments are assigned to the named local variables in a function body. See the Calls section for the rules governing this assignment. Syntactically, any expression can be used to represent an argument; the evaluated value is assigned to the local variable. See also the parameter glossary entry, the FAQ question on the difference between arguments and parameters, and PEP 362 . Usually refers to an asynchronous generator function, but may refer to an asynchronous generator iterator in some contexts. In cases where the intended meaning isn’t clear, using the full terms avoids ambiguity. An asynchronous generator function may contain$_{await}$ expressions as well as$_{async for}$, and$_{async}$ with statements. This is an asynchronous iterator which when called using the$_{__anext__()}$ method returns an awaitable object which will execute the body of the asynchronous generator function until the next$_{yield}$ expression. Each$_{yield}$ temporarily suspends processing, remembering the location execution state (including local vari- ables and pending try-statements). When the asynchronous generator iterator effectively resumes with another awaitable returned by$_{__anext__()}$ , it picks up where it left off. See PEP 492 and PEP 525 . See also text file for a file object able to read and write$_{str}$ objects. Some operations need the binary data to be mutable. The documentation often refers to these as “read- write bytes-like objects”. Example mutable buffer objects include$_{bytearray}$and a$_{memoryview}$of a $_{bytearray}$. Other operations require the binary data to be stored in immutable objects (“read-only bytes- like objects”); examples of these include$_{bytes}$and a$_{memoryview}$of a$_{bytes}$object. bytecode Python source code is compiled into bytecode, the internal representation of a Python program in the CPython interpreter. The bytecode is also cached in$_{.pyc}$ files so that executing the same file is faster the second time (recompilation from source to bytecode can be avoided). This “intermediate language” is said to run on a virtual machine that executes the machine code corresponding to each bytecode. Do note that bytecodes are not expected to work between different Python virtual machines, nor to be stable between Python releases. bytes-like object An object that supports the bufferobjects and can export a C- contiguous buffer. This includes all $_{bytes}$,$_{bytearray}$ , and$_{array.array}$ objects, as well as many common$_{memoryview}$objects. Bytes- like objects can be used for various operations that work with binary data; these include compression, saving to a binary file, and sending over a socket. binary file A file object able to read and write bytes-like objects . Examples of binary files are files opened in binary mode ($_{'rb'}$ ,$_{'wb'}$ or$_{'rb+'}$ ),$_{sys.stdin.buffer}$ ,$_{sys.stdout.buffer}$ , and instances of$_{io.}$ BytesIO and$_{gzip.GzipFile}$ . BDFL Benevolent Dictator For Life, a.k.a. Guido van Rossum, Python’s creator. awaitable An object that can be used in an $_{await}$expression. Can be a coroutine or an object with an __await__() method. See also PEP 492 . attribute A value associated with an object which is referenced by name using dotted expressions. For example, if an object o has an attribute a it would be referenced as o.a . asynchronous iterator An object that implements the __aiter__() and __anext__() methods. __anext__ must return an awaitable object. $_{async for}$resolves the awaitables returned by an asynchronous iterator’s __anext__() method until it raises a StopAsyncIteration exception. Introduced by PEP 492 . asynchronous iterable An object, that can be used in an$_{async for}$statement. Must return an asynchronous iterator from its$_{__aiter__()}$ method. Introduced by PEP 492 . asynchronous generator iterator An object created by a asynchronous generator function. asynchronous generator A function which returns an asynchronous generator iterator . It looks like a coroutine function defined with$_{async def}$except that it contains$_{yield}$ expressions for producing a series of values usable in an$_{async for}$loop. asynchronous context manager An object which controls the environment seen in an async with statement by defining __aenter__() and __aexit__() methods. Introduced by PEP 492 .