Convert an excel or spreadsheet column letter to its number in Pythonic fashion

Question

Is there a more pythonic way of converting excel-style columns to numbers (starting with 1)?

Working code up to two letters:

Answer 1

This should do, in VBA, what you're looking for:

Function columnNumber(colLetter As String) As Integer

    Dim colNumber As Integer
    Dim i As Integer

    colLetter = UCase(colLetter)
    colNumber = 0
    For i = 1 To Len(colLetter)
        colNumber = colNumber + (Asc(Mid(colLetter, Len(colLetter) - i + 1, 1)) - 64) * 26 ^ (i - 1)
    Next

    columnNumber = colNumber

End Function

You can use it as you would an Excel formula--enter column, in letters, as a string (eg, "AA") and should work regardless of column length.

Your code breaks when dealing with three letters because of the way you're doing the counting--you need to use base 26.