Python reads an Excel table, gets an empty cell, gets an error, or gets an empty string?

After testing, it is found that when a row has the most columns, an error will be reported when the next column is obtained. When other rows do not have the most columns, no error will be reported when the next column is obtained. Reason: Excel creates the memory space according to the rectangular area, the length is the longest column, and the height is the most row. Even if the user does not enter certain cells, Excel fills them with empty strings by default.

For example: if I have an excel table a,b,c, 1,2,k then its real fields are 3 horizontal and 3 vertical. You get (0,0), you get a, you get (0,3), you get an error, you get (1,2), you get an empty string, you get (1,3), you get an error, you get (0,2), you get an empty string, you get (1,2), you get k.