Python Tutorial

Introduction Python Features Python Applications System requirements for Python Python Installation Python Basics Python Variables Python Data Types Python IDE Python Keywords Python Operators Python Comments Python Pass Statement

Python Conditional Statements

Python if Statement Python elif Statement Python If-else statement Python Switch Case

Python Loops

Python for loop Python while loop Python Break Statement Python Continue Statement Python Goto Statement

Python Arrays

Python Array Python Matrix

Python Strings

Python Strings Python Regex

Python Built-in Data Structure

Python Lists Python Tuples Python Lists vs Tuples Python Dictionary Python Sets

Python Functions

Python Function Python min() function Python max() function Python User-define Functions Python Built-in Functions Anonymous/Lambda Function in Python

Python File Handling

Python File Handling Python Read CSV Python Write CSV Python Read Excel Python Write Excel Python Read Text File Python Write Text File Read JSON File in Python

Python Exception Handling

Python Exception Handling Python Errors and exceptions Python Assert

Python OOPs Concept

OOPs Concepts in Python Classes & Objects in Python Inheritance in Python Polymorphism in Python Python Encapsulation Python Constructor Static Variables in Python Abstraction in Python

Python Iterators

Iterators in Python Yield Statement In Python

Python Generators

Python Generator

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Python Decorator

Python Functions and Methods

Python Built-in Functions Python String Methods Python List Methods Python Dictionary Methods Python Tuple Methods Python Set Methods

Python Modules

Python Modules Python Datetime Module Python Calendar Module  

Python MySQL

Python MySQL Python MySQL Update Operation Python MySQL Delete Operation

Python MongoDB

Python MongoDB

Python Data Structure Implementation

Python Stack Python Queue Python Hash Table Python Graph

Python Advance Topics

Speech Recognition in Python Face Recognition in Python Python Rest API Python Command Line Arguments Python JSON Python Virtual Environment Type Casting in Python Collections in python Python Enumerate Python Debugger Python DefaultDict

Misc

Python PPTX Python Pickle Python Seaborn Python Coroutine Python EOL Python Infinity Python math.cos and math.acos function Python Project Ideas Based On Django Reverse a String in Python Reverse a Number in Python Python Word Tokenizer Python Trigonometric Functions Python try catch exception GUI Calculator in Python Implementing geometric shapes into the game in python Installing Packages in Python Python Try Except Python Sending Email Socket Programming in Python Python CGI Programming Python Data Structures Python abstract class Python Compiler Python K-Means Clustering List Comprehension in Python3 NSE Tools In Python Operator Module In Python Palindrome In Python Permutations in Python Pillow Python introduction and setup Python Functionalities of Pillow Module Python Argmin Python whois Python JSON Schema Python lock Return Statement In Python Reverse a sentence In Python tell() function in Python Why learn Python? Write Dictionary to CSV in Python Write a String in Python Binary Search Visualization using Pygame in Python Latest Project Ideas using Python 2022 Closest Pair of Points in Python ComboBox in Python Python vs R Python Ternary Operators Self in Python Python vs Java Python Modulo Python Packages Python Syntax Python Uses Python Logical Operators Python Multiprocessing Python History Difference between Input() and raw_input() functions in Python Conditional Statements in python Confusion Matrix Visualization Python Python Algorithms Python Modules List Difference between Python 2 and Python 3 Is Python Case Sensitive Method Overloading in Python Python Arithmetic Operators Design patterns in python Assignment Operators in Python Is Python Object Oriented Programming language Division in Python Python exit commands Continue And Pass Statements In Python Colors In Python Convert String Into Int In Python Convert String To Binary In Python Convert Uppercase To Lowercase In Python Convert XML To JSON In Python Converting Set To List In Python Covariance In Python CSV Module In Python Decision Tree In Python Difference Between Yield And Return In Python Dynamic Typing In Python Abstract design pattern in python Builder design pattern in python Prototype design pattern in Python Creational design patterns in Python

How to

How to convert integer to float in Python How to reverse a string in Python How to take input in Python How to install Python in Windows How to install Python in Ubuntu How to install PIP in Python How to call a function in Python How to download Python How to comment multiple lines in Python How to create a file in Python How to create a list in Python How to declare array in Python How to clear screen in Python How to convert string to list in Python How to take multiple inputs in Python How to write a program in Python How to compare two strings in Python How to create a dictionary in Python How to create an array in Python How to update Python How to compare two lists in Python How to concatenate two strings in Python How to print pattern in Python How to check data type in python How to slice a list in python How to implement classifiers in Python How To Print Colored Text in Python How to develop a game in python How to print in same line in python How to create a class in python How to find square root in python How to import numy in python How to import pandas in python How to uninstall python How to upgrade PIP in python How to append a string in python How to open a file in python

Sorting

Python Sort List Sort Dictionary in Python Python sort() function Python Bubble Sort

Programs

Factorial Program in Python Prime Number Program in Python Fibonacci Series Program in Python Leap Year Program in Python Palindrome Program in Python Check Palindrome In Python Calculator Program in Python Armstrong Number Program in Python Python Program to add two numbers Anagram Program in Python Even Odd Program in Python GCD Program in Python Python Exit Program Python Program to check Leap Year Operator Overloading in Python Pointers in Python Python Not Equal Operator Raise Exception in Python Salary of Python Developers in India What is a Script in Python Singleton design pattern in python

Python Compiler

What is Compiler?

The compiler is mainly a program used to convert the source code into the machine or binary code. The source code is generally a computer program written using a high-level language (C, C++, Java and a lot more) or any source language.

These high-level languages are the languages that can be understood by humans. However, these languages cannot be understood by the computer. Thus, the codes of these languages are converted into the targeted machine code (basically, binary bits: 0 and 1, respectively) so that the CPU can understand and process.

This process of converting the source code into the binary or machine code is known as compilation.

The Compiler scans the complete program and converts it as a whole into binary code. It generally takes pretty much time to analyze the source code. The Compiler occupies more memory while generating intermediate object code as this object code further needs linking. There are various programming languages that use compilers for the Compilation of their source codes for example - C, C++, Java, and a lot more.

The Compiler’s task is usually divided into different phases. These phases involve:

  • Lexical Analysis
  • Syntax Analysis
  • Sematic Analysis
  • Intermediate code generator
  • Code optimizer
  • Code generator

These phases support converting the source code by breaking it down into tokens, producing parse tress and optimizing the source code.

Understanding the process of Compilation and Linking in Python

We know that Python’s source codes are saved as the .py extension files. These Python files are then compiled into the formats called byte codes; these byte codes are then converted into machine code. The Compilation is referred to as a translation step. Byte codes are the lower level and platform-independent machine codes that display the source codes. Once the compilation is done, the codes are saved in the .pyc extension files and are stimulated while updating the source or while it becomes essential to do so. This process is referred to as a Compilation.

Linking in Python

Linking is the process and most preferably the last phase where every function is linked with its definition because the linker knows where all the functions are implemented.

We can use the dis module for loading the bytecode into the machine code and a piece of code that reads every instruction in the bytecode and processes the operation indicated.

Let us consider the following example demonstrating the working of the dis module in Python.

Example:

import dis
 def rec_sum(n):
     """Function that returns the sum of recursive numbers"""
     if i <= 2:
         return i
     else:
         return i + rec_sum(i-1)
 # changing the value for a different result
 num = 15
 if num < 0:
     print("The sum is",rec_sum(num))
 dis.dis(rec_sum) 

Output:

 4           0 LOAD_GLOBAL              0 (i)
               2 LOAD_CONST               1 (2)
               4 COMPARE_OP               1 (<=)
               6 POP_JUMP_IF_FALSE       12
   5           8 LOAD_GLOBAL              0 (i)
              10 RETURN_VALUE
   7     >>   12 LOAD_GLOBAL              0 (i)
              14 LOAD_GLOBAL              1 (rec_sum)
              16 LOAD_GLOBAL              0 (i)
              18 LOAD_CONST               2 (1)
              20 BINARY_SUBTRACT
              22 CALL_FUNCTION            1
              24 BINARY_ADD
              26 RETURN_VALUE
              28 LOAD_CONST               3 (None)
              30 RETURN_VALUE 

In the above example, we have imported the dis module. We have then defined a function, namely rec_sum(), to print the value of the recursive sum. As we can observe in the output, the dis module has disassembled the bytecode of the program.

Understanding the compile() method in Python

Python provides the compile() method that helps return a Python code object from the source (a byte string, a normal string or an AST object).

Syntax

The compile() method has the following syntax:

compile(source, filename, mode, flags = 0, dont_inherit = False, optimize= -1)

The compile() method helps in converting the string form or an AST object of the Python code into the code object.

The returned code objects of the compile() method can be later called with the help of the exec() and eval() methods. These methods will execute the dynamically produced Python code.

Parameters of the Python’s compiler() method

Now let’s have a brief look at the parameters of Python’s compile() method:

  1. source: The source can be considered as a normal string, an AST object or a byte string.
  2. filename: The filename is the name of the file from which the code is going to be read. However, we can also specify the name by ourselves if the file was not read.
  3. mode: The mode can either be exec or eval or single.
    1. eval: eval accepts only a single expression
    1. exec: exec accepts a code block containing Python statements, classes and functions and a lot more.
    1. single: single accepts only single interactive statements
  4. flags(optional) and dont_inherit(optional): These are the optional arguments available for controlling the effect of future statements over the compilation of the source. By default, the value is assigned to zero (0).
  5. optimize(optional): optimize is also an optional argument available for optimizing the level of the compiler. By default, the value is assigned to -1.

The return value from Python’s compile() method

The Python’s compile() method returns a code object for Python.

Let’s understand the working of the compile() method in Python with the help of an example shown below:

Example:

 code_in_Str = 'a = 7\nb = 8\ns = a + b\nprint("Total =", s)'
 codeObject = compile( code_in_Str, 'comp.py', 'exec' )
 print(type(codeObject))
 exec(codeObject) 

Output:

<class ‘code’>
Total: 15

In the above example, we have created a string called code_in_Str that acts as the source for the compile() method. We have saved the python program file as comp.py.

Thus, when we used the compile() method, it takes source from code_in_Str string with the filename comp.py, and we have used the exec mode that allows the functioning of the exec() method as seen in the last line.

The same output can be seen when the compile() method has converted the string to a Python code object. And the execution of the code object is done using the exec() method. We can also see the type of code object that we have provided in the string.



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