Python (i)

A. Hello World program

Create a python file in Pycharm

Run results

Rules for variable definitions:

• Variable names can only be any combination of letters, numbers, or underscores
• The first character of a variable name cannot be a number
• The following keywords cannot be declared as variable names
  [' and ', ' as ', ' assert ', ' Break ', ' class ', ' Continue ', ' Def ', ' del ', ' elif ', ' Else ', ' except ', ' exec ', ' finally ', ' for ', ' F ' Rom ', ' Global ', ' if ', ' import ', ' in ', ' was ', ' lambda ', ' not ', ' or ', ' pass ', ' print ', ' raise ', ' return ', ' try ', ' while ', ' WI Th ', ' yield ']

Assigning values to variables

Note: in Python3. UFT-8 encoding is supported directly in X without the need to start labeling in the file. In addition, Chinese variables are supported in Python3

Comments:

When line comment: # is commented content

Multi-line Comment: ' Annotated content '

About single and double quotation marks:

Single and double quotes in Python are not removed, quotation marks can be applied in quotation marks without causing errors

About three quotes:

13 quotation marks for multi-line comments

23 quotation marks can represent multi-line content, formatted output of multi-line content

1.

2.

3.

Note: Not recommended method Three, method three need to strictly remember the variable order

User input:

Note: input is a string type and must be cast with an int () If you need to reshape the value. You can also cast to a string using str ().

If you do not want to enter the password visible, you can use the Getpass method in the Getpass module:

SELECT statement:

If...else

If...elif...else

Loop structure:

1.for Loop:

2while Loop:

Python (i)