Python Learning notes-3 operators and expressions

① expression: A formula that combines different data (including functions, variables) with operators according to certain rules

② operator :

Arithmetic operators :

+ addition operator

-Subtraction operator

* Multiplication operator

/division operator, Integer and integer can only be divided into integers, if you want to get a fractional part, to add a decimal point after a number as 3/2 can only get 1, if you want to get 1.5, you need to do this: 3.0/2 can get 1.5

The integer division operator, regardless of the result of dividing two numbers, has no fractional part, and the result is to the whole number of parts

* * Sub-square operator, e.g. three of four-square 3**4

The remainder operator, the result of the residual

Assignment operators:

+ =, plus equals, such as a+=10 equivalent to a=a+10, that is, the first operation A+10, and then assigned to a

-=, minus equals

*=, multiply equals

/=, except equal to

=, general assignment method, direct assignment

%=, to seek the remainder equals

Relational operators

= =, exactly equal to

=, equals

, Greater than

<, less than

<=, less than or equal to

>= greater than or equal to

! = does not equal

logical operators

And, logically with, two or more conditions are established at the same time is only established

Or, logical OR, as long as there is a condition to be established immediately

Not, logical non, negate

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Raw_input () reads the user input, which is read by default as a string

int () casts a string to a number

Python Learning notes-3 operators and expressions