I have a Pandas dataframe that I need to sort by the data columns' maximum values. I am having trouble performing the sort because all of the sorting examples that I have found operate on all of the columns in the dataframe when performing the sort. In this case I need to sort only a subset of the columns. The first column contains a date, and the remaining 90 columns contain data. The 90 data columns are currently sorted alphabetically by their column name. I would like to sort them in decreasing order of their maximum value, which happens to be in the last row.
In the bigger scheme of things, this question is about how to perform sorting on a range of columns within a dataframe, rather than sorting all of the columns in the dataframe. There may be cases, for example, where I need to sort only columns 2 through 12 of a dataframe, while leaving the remaining columns in their existing order.
Here is a sample of the unsorted dataframe:
df.tail()
Date ADAMS ALLEN BARTHOLOMEW BENTON BLACKFORD BOONE BROWN ... WABASH WARREN WARRICK WASHINGTON WAYNE WELLS WHITE WHITLEY
65 2020-05-10 8 828 356 13 14 227 28 ... 64 12 123 48 53 11 149 22
66 2020-05-11 8 860 367 16 14 235 28 ... 67 12 126 48 56 12 161 23
67 2020-05-12 8 872 371 17 14 235 28 ... 67 12 131 49 56 12 162 23
68 2020-05-13 9 897 382 17 14 249 29 ... 68 12 140 50 58 13 164 27
69 2020-05-14 9 955 394 21 14 252 29 ... 69 12 145 50 60 15 164 28
I would like to perform the sort so that the column with the largest value in row 69 is placed after df['Date'], with the columns ordered so that the values in row 69 decrease from left to right. Once that is done, I'd like to create a series containing the column headers, to generate rank list. Using the visible columns as an example, the desired list would be:
rank_list=[ "ALLEN", "BARTHOLOMEW", "BOONE", "WHITE", "WARRICK", ... "BLACKFORD", "WARREN", "ADAMS" ]
My biggest hurdle at present is that when I perform the sort I'm not able to exclude the Date column, and I'm receiving a type error:
TypeError: Cannot compare type 'Timestamp' with type 'int'
I am new to Pandas so I apologize if there is a solution to this problem that should be obvious. thanks.