Python Basics 2

1,pycharm Installation and use

Community Edition

Professional Edition English version

2, formatted output: %s%d%f

3,while ... Else

when the while loop is interrupted by A break, it does not go to the else program

4, operator

logical operator and with (0 with zero) or or (or a get one) not non-

first Case The logical operators are all comparison operations before and after

Priority level: ()> Not >and > or, same level from left to right

The second case The logical operators are all numbers before and after

x or Y, X is true, the value is x,x is false, and the value is y;

X and Y, X is true, the value is y,x false, and the value is x.

Conversion of bool value

INT----->bool not 0 is True , 0 is False

Bool----> int True is 1 , false is 0 .

Numbers and

5, the first knowledge of coding

The storage of computer files, and the transfer of files, are all 0101

primary password This ASCII letter special character number 8 bit = = 1 bytes

One byte represents one character

Characters: the smallest unit of content composition

Universal Code :Unicode creates a character with two bytes at the beginning of its creation.

Upgrade Four bytes represents a character.

Waste of resources

upgrade utf-8 to Unicode : Use a minimum of 8 digits to represent one character

China --Medium: three bytes

European Writings : two bytes

GBK: National standard. Letter one byte, man two bytes

Python Basics 2