【Python3.7学习笔记】三、变量和

print("Hello My Python World!")

 message = "Hello My Python World!"
 print(message)

message = "Hello World!"
print(mesage1)

# -*- coding: utf-8 -*-
message = "我是一个程序猿"
print(message)

message = '我是一个python程序猿'
print(message)

message = '我是一个"python"程序猿'
print(message)

message = "我是一个'程序猿'"
print(message)

message = "我是一个python`s程序猿"
print(message)

name = "ada lovelace"
print(name.title())

name = "Ada"
print("Ada=="+name)
print("Ada lower()=="+name.lower())
print("Ada upper()=="+name.upper())
print(name.lower().title())

name = "ADA"
print("ADA=="+name)
print("ADA lower()=="+name.lower())
print("ADA upper()=="+name.upper())
print(name.lower().title())

name = "ada"
print("ada=="+name)
print("ada lower()=="+name.lower())
print("ada upper()=="+name.upper())
print(name.lower().title())

# title()以首字母大写的方式显示每个单词，即将每个单词的首字母都改为大写
# lower()将单词的所有字母变成小写字母
# upper()将单词的所有字母变成大写字母

# 字符串使用+拼接
first_name = "ada"
last_name = "lovelace"
full_name = first_name +" "+last_name
print(full_name)

# 制表符\t或换行符\n添加空白
print("python")
print("\tPython")

print("Language:\nPython\nC\nJavaScript")

print("Language:\n\tPython\n\tC\n\tJavaScript")

# 删除空白
favorite_language = ' Python '
print(favorite_language)

# 两端删除空白
print(favorite_language.strip())

# 左侧删除空白
print(favorite_language.lstrip())

# 右侧删除空白
print(favorite_language.rstrip())

>>> 1+1
2
>>> 4-2
2
>>> 2*4
8
>>> 3/2
1.5

>>> 2**2
4
>>> 2**3
8
>>> 2**4
16
>>> 2**5
32
>>> 2**6
64
>>>

>>> 2+3*4
14
>>> (2+3)*4
20
>>>

>>> 0.1+0.1
0.2
>>> 0.2+0.2
0.4
>>> 2*0.1
0.2
>>> 2*0.3
0.6
>>>

>>> 0.1+0.2
0.30000000000000004
>>> 3*0.1
0.30000000000000004
>>>

# 使用函数str()避免类型错误
age = 23
#1 message = "Happy " + age + "rd Birthday!"
message = "Happy " + str(age) + "rd Birthday!"
print(message)

# 我是一个python程序猿
message = '我是一个python程序猿'
print(message)

>>> import this
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!