Analysis of the meaning and application characteristics of the Python numeric type

As a special general computer language, the Python programming language is used in a slightly different way than other common programming languages. So today, we can take a preliminary look at the application methods of the Python numeric type.

Description

The Python numeric type cannot be changed. That is to say, a new object is generated when the numeric value is changed.

Change

The following is an example of modifying or deleting a number type.

 
 

  
  
>>> a=1 
  
  
>>> id(a)  
  
  
3629968  
  
  
>>> a=2 
  
  
>>> id(a)  
  
  
3629956  
  
  
>>> del a  
  
  
>>> id(a)  
  
  
Traceback (most recent call last):  
  
  
File "<interactive input>", line 1, in <module> 
  
  
NameError: name 'a' is not defined  
  
  
>>> 
 
 

Python numeric type

Number types in Python: integer, long integer, Boolean, double-precision floating point, decimal floating point, and plural.

1) Integer

A) boolean type: there are only two integer values.

 
 

  
  
>>> a=True 
  
  
>>> int(a)  
  
  
1  
  
  
>>> a=False 
  
  
>>> int(a)  
  
  
0  
  
  
>>>   
  
  
>>> bool(1)  
  
  
True  
  
  
>>> bool(True)  
  
  
True  
  
  
>>> bool('1')  
  
  
True  
  
  
>>> bool('0')  
  
  
True  
  
  
>>> bool(0)  
  
  
False  
  
  
>>> bool('')  
  
  
False  
  
  
>>> bool([])  
  
  
False  
  
  
>>> a=1 
  
  
>>> b=a<2 
  
  
>>> b  
  
  
True  
  
  
>>> True,FalseFalse=False,True  
  
  
>>> bool(True)  
  
  
False  
  
  
>>> bool(False)  
  
  
True 
 
 

B) integer and long integer

After Python 2.2, you can think of integer and long integer as the same thing.

 
 

  
  
>>> 10000**8  
  
  
100000000000000000000000000000000L  
  
  
>>> 10**8  
  
  
100000000  
  
  
>>> 
 
 

2) double-precision floating point number

• Basic Application Syntax of Python constructor list
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Similar to double in C.

3) plural

The plural number in the Python numeric type consists of a real number and a virtual number: real + imagj.

Negative attributes:

Num. real the real part of the plural

Num. imag the imaginary part of the plural number

Num. conjugate () returns the combination of the complex numbers.

 
 

  
  
>>> a=1+3j  
  
  
>>> b=1+3j  
  
  
>>> id(a)  
  
  
19911528  
  
  
>>> id(b)  
  
  
19911600  
  
  
>>> a.real  
  
  
1.0  
  
  
>>> a.imag  
  
  
3.0  
  
  
>>> a.conjugate  
  
  
<built-in method conjugate of complex object at 0x012FD368> 
 
 

4) decimal floating point number

 
 

  
  
Decimal  
  
  
>>> from decimal import Decimal  
  
  
>>> Decimal("0.1")*Decimal("3.1415926")  
  
  
Decimal("0.31415926") 
 
 

The above is our introduction to the Python numeric type.