Question

我正在编写一个代码，程序从文件中读取数据，然后读取数据，如果列表中存在特定的单词，则允许用户修改其数量。那么问题是如何在for循环搜索单词时获取for循环中的迭代次数（行号）

我的代码：

f= open('guru99.txt','r')

action = int(input('Enter number'))
if action == 1:
    for line in lines:
        if 'banana' in line:
            print(line)
            print('You already purchased banana! You can change the quantity')
            edit = line.split()
            qty = int(input('Enter new quanity'))
            print(bline)
        else:
            continue

例如，如果在第3行找到 banana 这个词。如何编辑此程序以显示for循环的迭代编号或索引

Answer 1

添加一个跟踪当前传递的迭代次数的变量：

f= open('guru99.txt','r')
lines = f.readlines()
i =1
for line in lines:
    print([i],line)
    i = i+1
count = 0
action = int(input('Enter line number'))
if action == 1:
    for line in lines:
        count += 1
        print(count)
        if 'banana' in line:
            print(line)
            print('You already purchased banana! You can change the quantity')
            edit = line.split()
            qty = int(input('Enter new quanity'))
            edit[-1] = (int(edit[-1]) / float(edit[3]))
            bprice = (edit[-1])
            edit[3] = str(qty)
            edit[-1] = str(int(qty * bprice))
            bline = ' '.join(edit)
            print(bline)
        else:
            continue

Answer 2

f= open('guru99.txt','r')
lines = f.readlines()
i =1
line_counter = 0
for line in lines:
    print([i],line)
    i = i+1
    action = int(input('Enter line number'))
    if action == 1:
       for line in lines:
          line_counter += 1
          if 'banana' in line:
             print('You are on line: ' + str(line_counter)
             print('You already purchased banana! You can change the quantity')
             edit = line.split()
             qty = int(input('Enter new quanity'))
             edit[-1] = (int(edit[-1]) / float(edit[3]))
             bprice = (edit[-1])
             edit[3] = str(qty)
             edit[-1] = str(int(qty * bprice))
             bline = ' '.join(edit)
             print(bline)
          else:
             continue

Answer 3

您可以尝试使用while循环替换它：

i = 0
while i < len(lines):
   # Your code here
   i = i + 1

i等于迭代，lines[i]等于当前行。

计算for循环中的迭代次数

3 个答案: