Retrieving value from Excel table from an intersection of values using Python

Question

I have a table in Excel and I want to be able to read it (I know how to achieve this) but also tell Python that if there are certain values of d, D and B, for it to return the dimension value in the top first row as a variable in my programme. I have read various posts concerning intersections and I am not sure whether they were what I was looking for therefore I have decided to ask my own question.

My Excel table is in the format as follows (just a small example since I can't post images):

                      Dimensions
d      D  |  17      27    37     47       17-47
          |                B           |   rsmin
0.6    2     0.8     -     -       -       0.05
1    2.5     1       -     -       -       0.05
1.5    3     1       -     1.8     -       0.05
2      4     1.2     -     2       -       0.05

If I take an example and I have a d = 2, D = 4 (these two values will always be in the same row) and B = 2. I therefore would like to return the value Dimension = 37 to my programme. I also have the problem that I have several worksheets to read so I will refer to this table as Table1 and I must initially read through all worksheets which include one table each in the same .xls file.

Answer 1

Here's how to search your table, based on guesses as to what you want. You should be able to do the loop-over-5-tables stunt yourself.

def search(table_iterator, d, D, B):
    headings = next(table_iterator)
    junk = next(table_iterator)
    key = [d, D]
    for row in table_iterator:
        if row[0:2] != key: continue
        for index, value in enumerate(row[2:-1]):
            if value == B: 
                return headings(2 + index)
    return None

Update after questions asked in comment:

"""This should return the dimension value I want?"""

Yes, it should. But it's a generalised approach. I don't answer "gimme teh codez" questions literally. You have to do some work, either to write a "table_iterator" suitable to the tool (presumably xlrd) with which you are reading the table(s), or treat it as pseudocode which you take as a guide and completely rewrite to suit the tool.

"""In the end I have compiled all my tables into one .xls document but using several worksheets. Is there a particular way I could go about searching all worksheets and then applying this code?"""

As I said, you should be able to do the loop-over-5-tables stunt yourself. Searching all worksheets and then applying this code seems a strange approach. You need to iterate over the worksheets, searching each one, until you find a matching row.