Question

我正在尝试使用条件语句遍历数据框。

我尝试拆分循环，它们都单独工作；但是，组合后，循环将在1次迭代后停止。

i=0 
stock = 100
cash = 0

for index, row in df2.iterrows(): 
    if df2.iloc[i][3] > df2.iloc[i+1][3]:          
        if stock == 0:                             #future stock is cheaper, but no stock to sell
           continue 
        else:
            cash = cash + df2.iloc[i][3] * stock   #future stock is cheaper, so sell
            stock = 0 
    else:                                          #future stock is more expensive, so buy 
        stock = round((cash/df2.iloc[i][3])-0.5) 
       cash = round((cash - stock*df2.iloc[i][3])-0.5)
    i+=1
i

打印i时应该给出一个数字列表（即循环在一次迭代后停止）时仅给出1

Answer 1

因为您在for循环之外打印i，所以不会得到数字列表，而只会得到i的最后一个值

也可能是复制/粘贴错误，但是您在stock = round((cash/df2.iloc[i][3])-0.5)之前缩进了很多。

您能举个例子说明数据框中的内容吗？

Answer 2

似乎您在df2行上使用循环，但是在循环中的任何地方都没有使用index和row。如果您要遍历df2中的每一行，那么我建议：

i=0 
stock = 100
cash = 0

for i in range(df2.shape[0]-1): # iterate over all rows except last iloc[i+1] is the last
    if df2.iloc[i][3] > df2.iloc[i+1][3]:          
        if stock == 0:                             #future stock is cheaper, but   no stock to sell
           continue 
        else:
            cash = cash + df2.iloc[i][3] * stock   #future stock is cheaper, so sell 
            stock = 0 
    else:                                          #future stock is more expensive, so buy 
        stock = round((cash/df2.iloc[i][3])-0.5) 
        cash = round((cash - stock*df2.iloc[i][3])-0.5)
print(i)

数据框循环停止

2 个答案: