python变量

1. 变量命名

变量名只能包含字母、数字和下划线。变量名不能以数字开头。
变量名不能包含空格，可使用下划线
python关键字和函数名不能用作变量
慎用1和大写O
变量名默认用小写字母表示

2. 多个变量同时赋值

x,y,z = 1, 2, 3
print(f"{x} {y} {z}")

3. 常量

常量名默认用全大写字母

4. Python之禅

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!

美丽胜于丑陋。
显式比隐式好。
简单总比复杂好。
复杂总比隐晦好
扁平总比嵌套好。
稀胜于密。
可读性很重要。
特殊情况不足以打破规则。
尽管实用胜过纯粹。
错误永远不应该悄无声息地过去。
除非明确沉默。
面对歧义，拒绝猜测的诱惑。
应该有一种——最好只有一种——显而易见的方法来做到这一点。
尽管这种方式一开始可能并不明显，除非你是荷兰人。
现在总比没有好。
尽管从来没有比现在更好的了。
如果实现很难解释，那就是个坏主意。
如果实现很容易解释，那可能是个好主意。
名称空间是一个非常棒的想法——让我们做更多这样的事情吧！