bytecode python source code is compiled into bytecodethe internal representation of 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 avoidedthis "intermediate languageis said to run on virtual machine that executes the machine code corresponding to each bytecode do note that bytecodes are not expected to work between different python virtual machinesnor to be stable between python releases list of bytecode instructions can be found in the documentation for the dis module class template for creating user-defined objects class definitions normally contain method definitions which operate on instances of the class class variable variable defined in class and intended to be modified only at class level ( not in an instance of the classcoercion the implicit conversion of an instance of one type to another during an operation which involves two arguments of the same type for exampleint( converts the floating point number to the integer but in + each argument is of different type (one intone float)and both must be converted to the same type before they can be added or it will raise typeerror without coercionall arguments of even compatible types would have to be normalized to the same value by the programmere float( )+ rather than just + complex number an extension of the familiar real number system in which all numbers are expressed as sum of real part and an imaginary part imaginary numbers are real multiples of the imaginary unit (the square root of - )often written in mathematics or in engineering python has built-in support for complex numberswhich are written with this latter notationthe imaginary part is written with suffixe + to get access to complex equivalents of the math moduleuse cmath use of complex numbers is fairly advanced mathematical feature if you're not aware of need for themit' almost certain you can safely ignore them context manager an object which controls the environment seen in with statement by defining __enter__(and __exit__(methods see pep contiguous buffer is considered contiguous exactly if it is either -contiguous or fortran contiguous zero-dimensional buffers are and fortran contiguous in one-dimensional arraysthe items must be laid out in memory next to each otherin order of increasing indexes starting from zero in multidimensional -contiguous arraysthe last index varies the fastest when visiting items in order of memory address howeverin fortran contiguous arraysthe first index varies the fastest coroutine coroutines is more generalized form of subroutines subroutines are entered at one point and exited at another point coroutines can be enteredexitedand resumed at many different points they can be implemented with the async def statement see also pep coroutine function function which returns coroutine object coroutine function may be defined with the async def statementand may contain awaitasync forand async with keywords these were introduced by pep cpython the canonical implementation of the python programming languageas distributed on python org the term "cpythonis used when necessary to distinguish this implementation from others such as jython or ironpython decorator function returning another functionusually applied as function transformation using the @wrapper syntax common examples for decorators are classmethod(and staticmethod(the decorator syntax is merely syntactic sugarthe following two function definitions are semantically equivalentdef ) staticmethod( (continues on next page