OpenPyXL - 如何根据某些条件从 Excel 文件中删除行？

Question

我想从 excel 文件中删除行，知道这些值。我使用 openpyxl：

key_values_list 是带有数字的列表（所有都存在于 excel 文件中，列上）

   wb = load_workbook(src)
    sheet = wb['Sheet 1']

    for i in range(2, sheet.max_row + 1):
        if sheet.cell(row=i, column=1).value in key_values_list:
            sheet.delete_rows(i, 1)
    wb.save(src)

上面的代码不会删除所有对应的行

Answer 1

在 for 循环中删除直接元素时总会遇到问题。考虑具有 12 行及其各自行值的工作表的以下代码：

for i in range(1, sh.max_row + 1):
    print(sh.cell(row=i, column=1).value)

# 1 .. 12

现在看看当你开始删除东西时会发生什么：

for i in range(1, sh.max_row + 1):
    if sh.cell(row=i, column=1).value in [5,6,7]:
        sh.delete_rows(i, 1)
    print(f'i = {i}\tcell value (i, 1) is {sh.cell(row=i, column=1).value}')

# i = 1     cell value (i, 1) is 1
# i = 2     cell value (i, 1) is 2
# i = 3     cell value (i, 1) is 3
# i = 4     cell value (i, 1) is 4
# i = 5     cell value (i, 1) is 5
# i = 6     cell value (i, 1) is 7
# i = 7     cell value (i, 1) is 9
# i = 8     cell value (i, 1) is 10
# i = 9     cell value (i, 1) is 11
# i = 10    cell value (i, 1) is 12
# i = 11    cell value (i, 1) is None
# i = 12    cell value (i, 1) is None

您可以看到，在 期间i in [5, 6, 7]，行的移动从第 6 行开始，因为第 5 行已被删除，使原始第 6 行成为新行 5、原始第 7 行新行 6...等等。所以在下一次迭代中i = 6，单元格实际上是引用原始数据中第 7 行的值。您有效地跳过了第 6 行的迭代。

最简单的答案是使用while循环，而不是for：

i = 1
while i <= sh.max_row:
    print(f'i = {i}\tcell value (i, 1) is {sh.cell(row=i, column=1).value}')
    if sh.cell(row=i, column=1).value in [5,6,7]:
        sh.delete_rows(i, 1)
        # Note the absence of incremental.  Because we deleted a row, we want to stay on the same row because new data will show in the next iteration.
    else:
        i += 1
        # Because the check failed, we can safely increment to the next row.

# i = 1 cell value (i, 1) is 1
# i = 2 cell value (i, 1) is 2
# i = 3 cell value (i, 1) is 3
# i = 4 cell value (i, 1) is 4
# i = 5 cell value (i, 1) is 5 # deleted
# i = 5 cell value (i, 1) is 6 # deleted
# i = 5 cell value (i, 1) is 7 # deleted
# i = 5 cell value (i, 1) is 8
# i = 6 cell value (i, 1) is 9
# i = 7 cell value (i, 1) is 10
# i = 8 cell value (i, 1) is 11
# i = 9 cell value (i, 1) is 12

# verify the data has been deleted
for i in range(1, sh.max_row +1):
    print(sh.cell(row=i, column=1).value)

# 1
# 2
# 3
# 4
# 8
# 9
# 10
# 11
# 12

你现在可以看到虽然i没有达到 12，但每一行都被迭代了，因为i=5已经被处理了三次。

如果出于某种原因必须使用for循环进行迭代，则可能需要考虑一些替代方法，例如遍历副本或向后执行