Python Language Main Concepts And Summary

Why Python?

Python language core concepts¹:

• Python is a programming language that offers much more structure and support for large programs than shell scripts or batch files.
• Python has high-level data types built in, such as flexible arrays and dictionaries.
• Python allows you to split your program into modules that can be reused in other Python programs. It comes with a large collection of standard modules that you can use as the basis of your programs
• Python is an interpreted language, no compilation and linking is necessary. The interpreter can be used interactively.
• Statement grouping is done by indentation instead of beginning and ending brackets;
• no variable or argument declarations are necessary.
• Python is extensible, easy to add a new built-in function or module to the interpreter.

Python Interpreter

Python commands can handle arguments with the sys module. The script name and additional arguments are turned into a list of strings and assigned to the argv variable in the sys module. This list is accessible after executing import sys, for example with sys.argv[0].

Encoding

By default, Python source files are treated as encoded in UTF-8, this is equivalent to having # -*- coding: utf-8 -*- in scripts.

Numbers

Python supports several types of numbers:

int

class int(x=0)

class int(x, base=10)

Return an integer object constructed from a number or string x, or return 0 if no arguments are given

float

class float([x])

Return a floating point number constructed from a number or string x.

Decimal

class decimal.Decimal(value=“0”, context=None)¶

Construct a new Decimal object based from value.

Fraction

[sign] numerator [’/’ denominator]

A Fraction instance can be constructed from a pair of integers, from another rational number, or from a string.

And even complex numbers, (using j or J suffix to indicate the imaginary part e.g. 3+5j)