pandas multiple conditions based on multiple columns using np.where
Selection criteria uses Boolean indexing:
df['color'] = np.where(((df.A < borderE) & ((df.B - df.C) < ex)), 'r', 'b')>>> df A B C color0 0 11 20 r1 1 12 19 r2 2 13 18 r3 3 14 17 b4 4 15 16 b5 5 16 15 b6 6 17 14 b7 7 18 13 b8 8 19 12 b9 9 20 11 b
wrap the IF in a function and apply it:
def color(row): borderE = 3. ex = 0. if (row.A > borderE) and( row.B - row.C < ex) : return "somestring" else: return "otherstring"df.loc[:, 'color'] = df.apply(color, axis = 1)Yields:
A B C color0 0 11 20 otherstring1 1 12 19 otherstring2 2 13 18 otherstring3 3 14 17 otherstring4 4 15 16 somestring5 5 16 15 otherstring6 6 17 14 otherstring7 7 18 13 otherstring8 8 19 12 otherstring9 9 20 11 otherstring