Question

我是Python的新手，我的功能没有按预期工作。我试图在列表list_alt [i]中保存一些值，但如果我调用if或else语句之外的值，我只得到None。

import os.path
import xlrd
import sys
import argparse

def readExcel():
     workbook = xlrd.open_workbook(path)
     sheet = workbook.sheet_by_index(0)
     sheet = workbook.sheet_by_index(0)
     j=0
     for row in range(sheet.nrows):
          j += 1
     rownumber=j
     print (rownumber)

     k=0
     i=0
     list_alt=[None]*j 
     list_neu=[None]*j
     while (i<j-10):
          #get first row values
          temp = sheet.cell_value(k,0).replace('www.website.com/','')   
          #get second row values
          temp2 = sheet.cell_value(k,1)
          if "http:" in temp2:
               temp2 = sheet.cell_value(k,1).replace('http:','https:')
               list_neu[i]=temp2
               list_alt[i]=temp
               k+=0
               i+=1
          else:
               list_neu[i]=temp2
               list_alt[i]=temp
               #i can print the values here
               print (list_alt[i])
               print (list_neu[i]) 
               i+=1
               k+=1

          #I cant print for the values here anymore
          print (list_alt[i])
          print (list_neu[i])
          print (i)

     return list_alt, list_neu

Answer 1

if/else增加后，> i以后的行会被执行，因此它会打印None，因为这确实是{的值{ {1}}。无论如何，您的函数应返回正确的值。如果您希望看到刚插入的值，请考虑两种可能的更改：

将list_alt[i]增加为while循环中的最后一行

i而不是

Answer 2

如果您获得IndexError，则应该在使用之前通过索引i来增加list_alt[i]。

import os.path
import xlrd
import sys
import argparse

def readExcel():
workbook = xlrd.open_workbook(path)
sheet = workbook.sheet_by_index(0)
sheet = workbook.sheet_by_index(0)
j=0
for row in range(sheet.nrows):
    j += 1
rownumber=j
print (rownumber)

k=0
i=0
list_alt=[None]*j 
list_neu=[None]*j
while (i<j-10):
    temp = sheet.cell_value(k,0).replace('www.website.com/','') 
    temp2 = sheet.cell_value(k,1)
    if "http:" in temp2:
        temp2 = sheet.cell_value(k,1).replace('http:','https:')
        list_neu[i]=temp2
        list_alt[i]=temp
        k+=0
        # variable i is increased.
        i+=1
    elif "http" not in temp2:
        print ("not there")
        k+=1
    else:
        list_neu[i]=temp2
        list_alt[i]=temp
        print (list_alt[i])
        print (list_neu[i]) 
        # variable i is increased.
        i+=1
        k+=1

    # variable i is increased before.
    # you may purpose to read list_alt[i-1].
    print (list_alt[i])
    print (i)

return list_alt, list_neu

我希望我的回答很有帮助。：d

函数中的变量，也不在else语句后返回值

2 个答案: