Python 1.6 - Points to remember

 

Points to remember

·         Programs are written to get the machine working.

·         A programming language provides an interface to easily write programs.

·         The code written by a programmer in a high level language is called source code.

·         Object code – The code, after compiling C/C++ source code.

·         Byte code – The code, after compiling Python source code.

·         Machine code – The code which is directly executed by a processor.

·         Translator converts the source code into machine code.

·         Compiler executes the entire program in one go whereas Interpreter executes only one statement at a time.

·         Assembler converts the code written in Assembly language.   

·         Python was developed by Guido Van Rossum in the year 1991.

·         PVM (Python virtual machine) – It is a program that translates the Byte code into machine code. Since Interpreter in PVM does the main job, hence PVM is called an Interpreter.

·         The name Python has been picked from a comedy show namely “Monty python’s flying circus”.

·         Processor understands only machine code so our program is converted into machine code by a language translator.

·         There are two types of programming languages – Low level and high level. Machine and assembly languages are called low level languages. C, C++, Java, Python, Fortran etc. are called high level languages.

·         The compiler is much faster than the Interpreter.

·         Python is a compiled interpreted language.

·         CPython is the standard implementation of Python written in C language.

·         PyPy implementation has JIT compiler and Interpreter in its PVM While CPython has only Interpreter in its PVM.

·         Compilation process is hidden from the programmer in Python.

·         Python is a high level language that contains features of functional programming language like C and object oriented programming language like Java.

·         A Python program is first compiled into Byte code by Python compiler. This byte code is given to python Virtual Machine (PVM) which converts the Byte code to machine code so that the processor could execute it and display the result.

·         Python is a dynamically typed language which means we need not declare anything.

Comments

Post a Comment

Popular posts from this blog

Python 4.4 - Points to remember

  Points to remember ·          Operators are symbols used to perform some operations on operands. For example, in statement z=x+y, ‘+’ and ‘=’ are operators and ‘x’, ‘y’ and ‘z’ are operands. Addition operator is used here to add two operands ‘x’ and ‘y’ and assignment ‘=’ operator is used to assign the result of addition to operand ‘z’. ·          Operators which operate upon single operand are called Unary operators such as unary ‘+’ and unary ‘-’. For example, -5, -6.8 ·          Operators which operate upon two operands are called Binary operators such as addition, subtraction etc. For example, 5+7, 45-23, x+y, x/y ·          Arithmetic operators perform mathematical calculations such as addition, subtraction, multiplication, division. Modulus, floor division and exponentiation. ·          Assignment operator ‘=’ is used to assign a value to the left side variable. ·          There are compound assignment operators such as ‘+=’, ‘-=’, ‘*=’, ‘/=’, ‘//=’, ‘%=’ and ‘**=’
Read more

Python 3.6 - Points to remember

  Points to remember ·          A variable is any location in the computer’s memory which holds a value. ·          Python is memory efficient when dealing with variables as compared to other programming languages. ·          An identifier is a name given to a variable, function, class, list, tuple etc. Identifiers are used to identify things in Python. ·          Keywords are reserved words in Python that have some special meaning and they can only be used for pre-defined purpose. ·          Comments are always used to describe the features of a program and ignored by Python compiler and interpreter. ·          ‘#’ symbol is used to create a single line comment.    ·          Python does not recommend Triple double quotes (“””) or triple single quotes (‘’’) as multi line comment. ·          If triple double quotes (“””) or triple single quotes (‘’’) are written as the first statement of a class, function, module etc., then they are called Docstrings and can be used t
Read more

Python 3.3 - Datatypes in Python

Image
  Datatypes in Python As we have already discussed that data type refers to the type of data. So datatype implies that what type of data we can store in our Python program. There are two categories of datatypes available in Python – Built-in data types and User defined data types Built-in data types The data types which are pre-defined in Python are called built-in data types. These data types have already been developed by Python developer team which we can use directly. So we do not need to do anything in it. Following are built-in data types – ·          None ·          Numbers ·          Boolean ·          Sequences ·          Sets ·          Dictionary   These datatypes are further classified in some more datatypes. Observe the image below – 1.    The None Type The None Type represents no value. When we have no value to store in a variable or object then we can store None into that variable. There might be a case when we will need a value in a variable late
Read more