Learn Python with Steem #03 笔记
[toc]
划重点
- 分支结构
Python的分支结构用if、elif、else关键字来构造，可以是多分支，也可以嵌套。
- 代码块
Python中用缩进的方式构造代码块，程序的层次结构一目了然。
- 交互
使用input()函数输入数据，实现人与程序的交互。
编程练习
# 写作业
a = float(input('Please enter the first number: '))
b = float(input('Please enter the second number: '))
c = float(input('Please enter the last number: '))
if a > b and a > c:
print(a)
elif b > a and b > c:
print(b)
else:
print(c)
Please enter the first number: 55
Please enter the second number: 99
Please enter the last number: 22
99.0
计算busy机器人的点赞比例，这是它的js程序https://github.com/busyorg/busy-bot/
function getAccounts() {
const accounts = JSON.parse(process.env.STEEM_ACCOUNTS || '[]');
return accounts.map(account => ({
username: account.username,
wif: account.wif,
minVests: account.minVests || 20000000,
maxVests: account.maxVests || 4000000000000,
limitVests: account.limitVests || 10000000000000,
minPercent: account.minPercent || 6,
maxPercent: account.maxPercent || 2500,
}));
}
async function getVoteWeight(username, account) {
const mvests = await fetch(`https://steemdb.com/api/accounts?account[]=${username}`)
.then(res => res.json())
.then(res => res[0].followers_mvest);
if (mvests < account.minVests || mvests > account.limitVests) return 0;
const percent = parseInt((10000 / account.maxVests) * mvests);
return Math.min(Math.max(percent, account.minPercent), account.maxPercent);
}
# 这算是一个实际的例子吧，把它的计算部分抽出来，
# 用Python写一下，正好用到今天学的分支结构
# 查看followers_mvest
# https://steemdb.com/api/accounts?account=yjcps
minVests = 20000000
# maxVests = 4000000000000 # maxVests 不是这个值
maxVests = 5000000000000
limitVests = 10000000000000
minPercent = 6 / 100
maxPercent = 2500 / 100
followers_mvest = float(input('Input your followers_mvest: '))
# 93785952.40679602
if followers_mvest < minVests or followers_mvest > limitVests:
percent = 0
else:
percent = (10000 / maxVests) * followers_mvest
percent = min(max(percent, minPercent), maxPercent) / 100
print('Your Busy vote percent: {:.2%}'.format(percent))
Input your followers_mvest: 93785952.40679602
Your Busy vote percent: 0.19%
补充
比较运算符
<= < > >= 小于等于，小于，大于，大于等于
== != 等于，不等于
逻辑运算符
not or and 非，或，与
空语句 pass
pass 不是跳过某段程序的意思,它是是用来占位子的，为了让写的程序符合语法。
pass有两个用法用：
一是什么都不做，写个pass：
if True:
pass
另一个是，还没想好程序的某个功能怎么写，写个pass占位子:
def fun():
pass