A list of bytecode instructions can be found in the documentation for the dis module. The Python Language Reference, Release 3.9.5 119 def f(...): ... f =staticmethod(f) @staticmethod def f(...): ... decorator A function returning another function, usually applied as a function transformation using the$_{@wrapper}$ syntax. Common examples for decorators are$_{classmethod()}$ and$_{staticmethod()}$ . CPython The canonical implementation of the Python programming language, as distributed on python.org. The term “CPython” is used when necessary to distinguish this implementation from others such as Jython or IronPython. coroutine function A function which returns a coroutine object. A coroutine function may be defined with the $_{async def}$statement, and may contain$_{await}$ ,$_{async for}$, and$_{async with}$ keywords. These were introduced by PEP 492 . coroutine Coroutines are a more generalized form of subroutines. Subroutines are entered at one point and exited at another point. Coroutines can be entered, exited, and resumed at many different points. They can be implemented with the$_{async def}$statement. See also PEP 492 . context variable A variable which can have different values depending on its context. This is similar to Thread- Local Storage in which each execution thread may have a different value for a variable. However, with context variables, there may be several contexts in one execution thread and the main usage for context variables is to keep track of variables in concurrent asynchronous tasks. See$_{contextvars}$ . context manager An object which controls the environment seen in a$_{with}$ statement by defining$_{__enter__()}$ and$_{__exit__()}$ methods. See PEP 343 . complex number An extension of the familiar real number system in which all numbers are expressed as a sum of a real part and an imaginary part. Imaginary numbers are real multiples of the imaginary unit (the square root of$_{-1}$ ), often written$_{i}$ in mathematics or$_{j}$in engineering. Python has built-in support for complex numbers, which are written with this latter notation; the imaginary part is written with a j suffix, e.g., 3+1j . To get access to complex equivalents of the math module, use cmath . Use of complex numbers is a fairly advanced mathematical feature. If you’re not aware of a need for them, it’s almost certain you can safely ignore them. coercion The implicit conversion of an instance of one type to another during an operation which involves two arguments of the same type. For example, int(3.15) converts the floating point number to the integer 3 , but in 3+4.5 , each argument is of a different type (one int, one float), and both must be converted to the same type before they can be added or it will raise a$_{TypeError}$. Without coercion, all arguments of even compatible types would have to be normalized to the same value by the programmer, e.g.,$_{float(3)+4.5}$ rather than just$_{3+4.5}$ . class variable A variable defined in a class and intended to be modified only at class level (i.e., not in an instance of the class). contiguous A buffer is considered contiguous exactly if it is either C-contiguous or Fortran contiguous . Zero- dimensional buffers are C and Fortran contiguous. In one-dimensional arrays, the items must be laid out in memory next to each other, in order of increasing indexes starting from zero. In multidimensional C-contiguous arrays, the last index varies the fastest when visiting items in order of memory address. However, in Fortran contiguous arrays, the first index varies the fastest. class A template for creating user-defined objects. Class definitions normally contain method definitions which operate on instances of the class. callback A subroutine function which is passed as an argument to be executed at some point in the future. The decorator syntax is merely syntactic sugar, the following two function definitions are semantically equiv- alent: