列表元素在某些循环中被跳过，但在其他循环中不被跳过

Question

我正在尝试修改 python 中的列表，并且在我的循环中跳过了一些列表元素。列表是我要修改的列表。每个元素都是一个字符串列表。我试图从包含某些字符串的列表中删除元素，然后将每个元素中的最后一个字符串拆分为两个单独的字符串。第一个和最后一个 for 循环成功迭代了每个元素，但第二个 for 循环没有。第二个元素 ['FREE', 'Refrigerator freezer & gas炉.', 'Lancaster, PA'] 只出现在第一个和最后一个循环中。

for row in listings:
    print(row)
print(len(listings))
print("\n")

i = 0
for row in listings:
    print(i)
    print(row)
    if row[2] == 'Ships to you':
        del listings[i]
        print("removed")
    else:
        if len(row) == 4:
            del row[3]
        row.append(row[2].split(", ")[0].title())
        row.append(row[2].split(", ")[1])
        del row[2]
        print(row)
    print("----------------------------------------------------------")
    i = i+1

print("\n")
for row in listings:
    print(row)
print(len(listings))

['$375', 'Craftsman lt1000 riding mower/lawn tractor', 'Joppa, MD']
['$15', 'Woman’s black dress Shoe boot', 'Ships to you']
['FREE', 'Refrigerator freezer & gas stove.', 'Lancaster, PA']
['$30', 'Lawnmower Briggs and Stratton 6 HP motor', 'King of Prussia, PA']
['$10', 'Antique wooden ware', 'Lancaster, PA']
['$24', 'Joe Burrow Select Rookie', 'Ships to you']
['$400', 'Dining room set', 'Bel Air, MD']
['$15', 'Jade plant', 'Ephrata, PA']
['FREE', 'Free comfy couch', 'Philadelphia, PA']
['$30', 'Bookcase 30"x11.5"x39"', 'Reading, PA']
['$30', 'Need work 30 for all 3', 'Penns Grove, NJ']
['$15', 'women’s high heels', 'Glenside, PA']
['$8', 'Relic Floral Handbag', 'North Wales, PA']
['$200', 'Ge washer', 'Upper Darby, PA']
['$399', 'Ge washer', 'Upper Darby, PA']
['$10', 'Golf Clubs and Bag', 'Media, PA']
['$25', 'Jewelry', 'Port Deposit, MD']
['$300', 'New he electric dryer', 'Upper Darby, PA']
18


0
['$375', 'Craftsman lt1000 riding mower/lawn tractor', 'Joppa, MD']
['$375', 'Craftsman lt1000 riding mower/lawn tractor', 'Joppa', 'MD']
----------------------------------------------------------
1
['$15', 'Woman’s black dress Shoe boot', 'Ships to you']
removed
----------------------------------------------------------
2
['$30', 'Lawnmower Briggs and Stratton 6 HP motor', 'King of Prussia, PA']
['$30', 'Lawnmower Briggs and Stratton 6 HP motor', 'King Of Prussia', 'PA']
----------------------------------------------------------
3
['$10', 'Antique wooden ware', 'Lancaster, PA']
['$10', 'Antique wooden ware', 'Lancaster', 'PA']
----------------------------------------------------------
4
['$24', 'Joe Burrow Select Rookie', 'Ships to you']
removed
----------------------------------------------------------
5
['$15', 'Jade plant', 'Ephrata, PA']
['$15', 'Jade plant', 'Ephrata', 'PA']
----------------------------------------------------------
6
['FREE', 'Free comfy couch', 'Philadelphia, PA']
['FREE', 'Free comfy couch', 'Philadelphia', 'PA']
----------------------------------------------------------
7
['$30', 'Bookcase 30"x11.5"x39"', 'Reading, PA']
['$30', 'Bookcase 30"x11.5"x39"', 'Reading', 'PA']
----------------------------------------------------------
8
['$30', 'Need work 30 for all 3', 'Penns Grove, NJ']
['$30', 'Need work 30 for all 3', 'Penns Grove', 'NJ']
----------------------------------------------------------
9
['$15', 'women’s high heels', 'Glenside, PA']
['$15', 'women’s high heels', 'Glenside', 'PA']
----------------------------------------------------------
10
['$8', 'Relic Floral Handbag', 'North Wales, PA']
['$8', 'Relic Floral Handbag', 'North Wales', 'PA']
----------------------------------------------------------
11
['$200', 'Ge washer', 'Upper Darby, PA']
['$200', 'Ge washer', 'Upper Darby', 'PA']
----------------------------------------------------------
12
['$399', 'Ge washer', 'Upper Darby, PA']
['$399', 'Ge washer', 'Upper Darby', 'PA']
----------------------------------------------------------
13
['$10', 'Golf Clubs and Bag', 'Media, PA']
['$10', 'Golf Clubs and Bag', 'Media', 'PA']
----------------------------------------------------------
14
['$25', 'Jewelry', 'Port Deposit, MD']
['$25', 'Jewelry', 'Port Deposit', 'MD']
----------------------------------------------------------
15
['$300', 'New he electric dryer', 'Upper Darby, PA']
['$300', 'New he electric dryer', 'Upper Darby', 'PA']
----------------------------------------------------------


['$375', 'Craftsman lt1000 riding mower/lawn tractor', 'Joppa', 'MD']
['FREE', 'Refrigerator freezer & gas stove.', 'Lancaster, PA']
['$30', 'Lawnmower Briggs and Stratton 6 HP motor', 'King Of Prussia', 'PA']
['$10', 'Antique wooden ware', 'Lancaster', 'PA']
['$400', 'Dining room set', 'Bel Air, MD']
['$15', 'Jade plant', 'Ephrata', 'PA']
['FREE', 'Free comfy couch', 'Philadelphia', 'PA']
['$30', 'Bookcase 30"x11.5"x39"', 'Reading', 'PA']
['$30', 'Need work 30 for all 3', 'Penns Grove', 'NJ']
['$15', 'women’s high heels', 'Glenside', 'PA']
['$8', 'Relic Floral Handbag', 'North Wales', 'PA']
['$200', 'Ge washer', 'Upper Darby', 'PA']
['$399', 'Ge washer', 'Upper Darby', 'PA']
['$10', 'Golf Clubs and Bag', 'Media', 'PA']
['$25', 'Jewelry', 'Port Deposit', 'MD']
['$300', 'New he electric dryer', 'Upper Darby', 'PA']
16