Question

我正在写一个加权平均函数，有四个例外，我被困在如何设置这些条件中：

重量小于0或大于100
权重不等于100
权重和等级的数量不相等
成绩低于0

这是我的代码：

def weighted_avg(grades,weights):
    if sum(weights)<0:
        print("weight is less than 0")
    elif sum(weights)>100:
        print("weight is greater than 100")
    elif sum(weights)!=100:
        print("weight do not add to 100")
    elif for x in grades:
            if grades[x]<0:
            print("a grade is less than 0")
    else:
        s=0
        for x, y in zip(grades,weights):
            s+=x*y
        return s/sum(weights)

print(weighted_avg(grades4, weights4) == 85.0)

我不确定代码中缺少哪一部分。

Answer 1

我稍微整理了一下代码：

def weighted_avg(grades,weights):
    total_weight = sum(weights)
    if total_weight < 0 or total_weight > 100:
        print("Total weights not between 0 and 100")
    elif total_weight != 100:
        print("Total weights do not total 100")
    elif any(x < 0 for x in grades):
        print("A grade is less than 0")
    else:
        cumulative_grades = sum(x * y for x, y in zip(grades,weights))
        return cumulative_grades/total_weight
    return 0

print(weighted_avg(grades4, weights4) == 85.0)

您不能在for / if条件中使用elif语句，但是可以简化循环，以便对其进行检查（无需遍历整个循环）列表）使用any。您还应该计算一次total_weight，以减少重复计算。 sum也可以理解以获取总分。

Answer 2

我只是在更改订单时解决了这个问题

library(evaluate)
code <- c('x <- "don\'t you ignore me!"',
          'print(x)')
env <- list2env(list(y = 1:10), envir = parent.frame())
evaluate(code, envir = env)
replay(evaluate(code, envir = env))
## > x <- "don't you ignore me!"
## > print(x)
## [1] "don't you ignore me!"

如何在列表中设置条件以检查值是否小于0

2 个答案: