In the dataset df
below. I want to flag the anomalies in all columns except A
, B
,C
and L
.
Any value less than 1500 or greater than 400000 is regarded as an anomaly.
import pandas as pd # intialise data of lists data = { 'A':['T1', 'T2', 'T3', 'T4', 'T5'], 'B':[1,1,1,1,1], 'C':[1,2,3,5,9], 'D':[12005, 18190, 1034, 15310, 31117], 'E':[11021, 19112, 19021, 12, 24509 ], 'F':[10022,19910, 19113,19999, 25519], 'G':[14029, 29100, 39022, 24509, 412262], 'H':[52119,32991,52883,69359,57835], 'J':[41218, 52991,55121,69152,79355], 'K': [43211,8199991,56881,212,77342], 'L': [1,0,1,0,0], 'M': [31211,42901,53818,62158,69325], } # Create DataFrame df = pd.DataFrame(data) # Print the output. df
Attempt:
exclude_cols = ['A','B','C','L'] def flag_outliers(s, exclude_cols): if s.name in exclude_cols: return '' # or None, or whatever df.style() needs else: s = pd.to_numeric(s, errors='coerce') indexes = (s<1500)|(s>400000) return ['background-color: red' if v else '' for v in indexes] df.style.apply(lambda s: flag_outliers(s, exclude_cols), axis=1)
Result of the code:
Desired output should look like this:
Thanks for the effort!
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Answer
If you set the subset as the argument of the apply function, you will get what you want.
exclude_cols = ['A','B','C','L'] def flag_outliers(s, exclude_cols): if s.name in exclude_cols: print(s.name) return '' # or None, or whatever df.style() needs else: s = pd.to_numeric(s, errors='coerce') indexes = (s<1500)|(s>400000) return ['background-color: yellow' if v else '' for v in indexes] df.style.apply(lambda s: flag_outliers(s, exclude_cols), axis=1, subset=['D','E','F','G','H','J','K'])