# -*- coding:utf-8 -*-

#######变量和简单数据类型#######

print("Hello Python World!")

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Hello Python World!

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#变量（变量名的命名规则：只能包含字母、数字和下划线，只能以字母或下划线打头）

simple_message = "Hello Python Crash Course reader!"

print(simple_message)

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Hello Python Crash Course reader!

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simple_message = "Hello!" #修改变量值

print(simple_message)

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Hello!

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#使用方法修改字符串的大小写

name = "ada lovelace"

print(name.title()) #以首字母大写的方式显示每个单词

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Ada Lovelace

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name = "Ada Lovelace"

print(name.upper()) #将字符串改为全部大写

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ADA LOVELACE

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print(name.lower()) # 将字符串改为全部小写

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ada lovelace

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#拼接字符串

first_name = "ada"

last_name = "lovelace"

full_name = first_name + " " + last_name

print(full_name)

print("Hello " + full_name.title() + "!")

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ada lovelace

Hello Ada Lovelace!

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#使用制表符或换行符来添加空白

print("Python")

print(" Python") #制表符

print("Languages: Python C JavaScript") #换行符

print("Languages: Python C JavaScript")

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Python

Python

Languages:

Python

C

JavaScript

Languages:

Python

C

JavaScript

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#删除空白

favorite_language = " python "

print(favorite_language.rstrip()) #删除末尾空白

print(favorite_language.lstrip()) #删除开头空白

print(favorite_language.strip()) #删除两端空白

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python

python

python

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#数字

#整数的加（+）减（-）乘（*）除（/）运算

num1 = 2+3

num2 = 3-2

num3 = 2*3

num4 = 3/2

print(num1)

print(num2)

print(num3)

print(num4)

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5

1

6

1.5

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#乘方运算

num = 3**2

print(num)

num = 2 + 3*4

print(num)

num = (2 + 3) * 4

print (num)

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9

14

20

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#浮点数

num1 = 0.1 + 0.2

num2 = 2 * 0.1

print(num1)

print(num2)

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0.30000000000000004

0.2

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#将非字符串表示为字符串

age = 23

print("Happy " + str(age) + "rd Birthday!")

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Happy 23rd Birthday!

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