Enter python3 in xshell to enter Python commands, and Ctrl+d to exit
Variable naming rules: numbers, letters and underscores, cannot start with numbers
Numeric Type: Integer (int)
floating point number (float)
complex
Boolean type (bool): True and False
Numerical type operations: addition, subtraction, multiplication and division, a // b result is an integer (a is divided by b and rounded down), a % b (a is divided by b and the remainder is taken), a ** b (a to the power of b)
Sequence types: String, List, Tuple
Slicing operation of sequence type: sequence name [x:y:z] (left closed and right open), z is the step size, which can be negative
拆包：list = [1,2,3], a,b,c = list a=1,b=2,c=3
Member operators: in, not in returns boolean
Linux command: clear clear screen
> output redirection
touch: create file
rm delete files
rdmir delete directory