python中按单元格值的列索引号

Question

I am new to python and I am having a hard time with this issue and i need your help.

Q1 Q2 Q3 Q4 Q5
25 9  57 23 7
61 41 29 5  57
54 34 58 10 7
13 13 63 26 45
31 71 40 40 40
24 38 63 63 47
31 50 43 2  61
68 33 13 9  63
28 1  30 39 71

I have an excel report with the data above. I'd like to write a code that looks through all columns in the 1st row and output the index number of the column with S in the column value (ie, 3). I want to use the index number to extract data for that column. I do not want to use row and cell reference as the excel file gets updated regularly, thus d column will always move.

def find_idx():
    wb = xlrd.open_workbook(filename='data.xlsx')  # open report
    report_sheet1 = wb.sheet_by_name('Sheet 1')

    for j in range(report_sheet1.ncols): 
        j=report_sheet1.cell_value(0, j)
        if 'YTD' in j:
            break
        return j.index('Q4')
find_idx()

the i get "substring not found" erro

What i want is to return the column index number (ie, 3), so that i can call it easily in another code. How can i fix this?

Answer 1

Hass!

As far as I understood, you want to get the index of a column of an excel file whose name contains a given substring such as Y . Is that right?

If so, here's a working snippet that does not requires pandas:

import xlrd


def find_idx(excel_filename, sheet_name, col_name_lookup):
    """
    Returns the column index of the first column that
    its name contains the string col_name_lookup. If
    the col_name_lookup is not found, it returns -1.
    """
    wb = xlrd.open_workbook(filename=excel_filename)
    report_sheet1 = wb.sheet_by_name(sheet_name)

    for col_ix in range(report_sheet1.ncols):
        col_name = report_sheet1.cell_value(0, col_ix)

        if col_name_lookup in col_name:
            return col_ix

    return -1


if __name__ == "__main__":
    excel_filename = "./data.xlsx"
    sheet_name = "Sheet 1"
    col_name_lookup = "S"

    print(find_idx(excel_filename, sheet_name, col_name_lookup))

I tried to give more semantic names to your variables (I transformed your variable j into two other variables: col_ix (actual column index of the loop) and also the variable col_name which really stands for the column name.

This code assumes that the first line of your excel file contains the column names, and if your desired substring to be looked in each of these names is not found, it returns -1.