print("holleword!")
holleword!变量 变量的命名
1.变量名只能包含字母、数字和下划线 2.变量名不能包含空格，但可使用下划线来分隔其中的单词 3.不要将Python关键字和函数名用作变量名 4.变量名应既简短又具有描述性字符串
在Python中，用引号括起的都是字符串，其中的引号可以是单引号，也可以是双引号使用方法修改字符串的大小写
name="i love you" print(name.title())
I Love You
方法是Python可对数据执行的操作
在name.title()中,name后面的句点（.）让Python对变量name执行方法title()指定的操作
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
name="i lOVe you" print(name.lower())#全变成小写 print(name.upper())#全变成大写
i love you I LOVE YOU合并（拼接）字符串
Python使用加号（ + ）来合并字符串
name1="i love you" name2="ding cheng" name3=name1+name2+'！' print(name3)
i love youding cheng！转义字符
| 符号 | 说明 |
|---|---|
| n | 换行 |
| o | 表示一个空字符 |
| t | 横向制表符 |
| v | 纵向制表符 |
| a | 发出系统铃声 |
| b | 退格符 |
| r | 换行，并将当前的所有字符删掉 |
| f | 翻页 |
| ’ | 转义字符中的单引号 |
| " | 转义字符串中的单引号 |
print("\n")
print("i love youn")
print("ri love you")
使用制表符或换行符来添加空白
print("ti love you")
print("Languages:nPythonnCnJavaScript")
print("Languages:ntPythonntCntJavaScript")
删除空白
空白很重要，因为你经常需要比较两个字符串是否相同 Python能够找出字符串开头和末尾多余的空白。要确保字符串末尾没有空白，可使用方法strip()和rstrip()
name=' i love you ' print(name) print(name.rstrip()) print(name.strip())数字
1.整形 2.浮点型 3.str()函数将数字类型转化为字符串类型
a=1 b="i love" print(str(a)+b)import this
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!
