Self-hing Artificial intelligence------The variable cognition and operation of Python language

Today, I would like to introduce you to the number variable in Python, which is somewhat different from C++,java, let's introduce:

It is not necessary to declare a variable type in Python, but it is not worthwhile to assign a value to a variable before it is used, and the compiler will not pass

One: integer-----int:

The use of int in Python is roughly the same as C + +:

A=12

Print a

The result of the printing is: 12

Here I would like to first introduce you to a few functions

Type (): Returns the data type in parentheses

A= ' Hello '

Print type (a)

>>>><type ' String ' >

Len (): Returns the length of the variable in parentheses

Note: Using the Len () method is not possible with the int type

A= ' Hello World '

Print Len (a)

>> >11

Two: Float type------float

Floating-point types consist of integers and fractional parts, or they can be represented by scientific notation

a=1.23

Print type (a)

>> <type ' float ' >

Three: plural

Complex numbers are composed of real and imaginary parts, which can be a+bj or comple (A, B), and the real and imaginary parts of the complex numbers are floating point types

Four: Data type conversions

int (x): Converts x to an integer

Float (x): Converts x to a floating-point number

Complex (x): Converts x into a complex number, the real part is x, and the imaginary part is divided into 0

a=1.23

Print Complex (a)

>>> (1.23+0J)

Complex (x, y): Converts x and y to a complex number, the real part is divided into x,x and y is a numeric expression

V: constant

There are two more common constants in Python, Pi and E

Pi: Mathematical constant Pi (π)

E: Mathematical constants E. i.e. Natural number

Well, today's presentation is over and I hope to help you.

Self-hing Artificial intelligence------The variable cognition and operation of Python language