Python学习笔记DAY1

时间:2022-12-31 12:43:33
1、关于解释器:

(1)官网下载的python安装包里包含的解释器为CPython;

(2)IPython是基于CPython之上的一个交互式解释器,也就是说,IPython只是在交互方式上有所增强,但是执行Python代码的功能和CPython是完全一样的。

CPython用>>>作为提示符,而IPython用In [序号]:作为提示符。

(3)PyPy,运行速度最快的解释器;

2、在Linux系统上运行的时候,一般在coding的最开始会注明"#!/usr/bin/env python",含义是声明解释器在系统中的位置,可以直接执行代码;

3、变量命名:官方建议使用下划线"_"来对变量名进行标注,以解释变量名的含义,常量一般用大写字母来注明。

如:name_of_president = "Bing"

   PI = 3.1415          #圆周率的常量命名

4、关于字符编码:

 Python学习笔记DAY1

在Python 2.x的版本中,如包含中文字符,需在coding的最开始注明"-*- coding:utf-8 -*-",代表用utf-8进行处理;

5、注释:

两种方式:#和'''   '''

6、%s:字符串;%d:整型;%f:浮点型;

7、input()默认输入的是string,type()用来显示数据类型,需要进行强制转换(如需要);

几种打印方式:

8、判断:

Python学习笔记DAY1Python学习笔记DAY1
 1 _username = "bing"
2 _password = "bing"
3
4 username = input("username: ")
5 password = input("password: ")
6
7 if username == _username and password == _password:
8 print("Welcome {name} login...".format(name = username))
9 else:
10 print("Invalid username or password!!!")
View Code

  

9、循环

(1)while

Python学习笔记DAY1Python学习笔记DAY1
 1 #!/usr/bin/env python
2 #Author:Bing
3
4 age_of_oldboy = 56
5
6 count = 0
7
8 while count < 3:
9 guess_input = int(input("guess the age of oldboy: "))
10 if guess_input == age_of_oldboy:
11 print("yes, you got it !")
12 break
13 elif guess_input > age_of_oldboy:
14 print("think smaller !")
15 else:
16 print("think older !")
17 count += 1
18 if count == 3:
19 continue_confirm = input("Do you want to try again?")
20 if continue_confirm != "n":
21 count = 0
View Code

 

(2)for

Python学习笔记DAY1Python学习笔记DAY1
 1 #!/usr/bin/env python
2 #Author:Bing
3
4 age_of_oldboy = 56
5
6 count = 0
7
8 for i in range(3):
9 guess_input = int(input("guess the age of oldboy: "))
10 if guess_input == age_of_oldboy:
11 print("yes, you got it !")
12 break
13 elif guess_input > age_of_oldboy:
14 print("think smaller !")
15 else:
16 print("think older !")
View Code

 

10、break和continue:

break:跳出本循环;

continue:跳出本次循环,进入下次循环;