Pandas replace value with other column value

Question

I have a table and I want to replace column values with other columns values based on a condition:

Table:

A	B	C	D	E
x	1	test	fool	bar
y	3	test	fool	bar

If column C contains the word test -> value should be replaced with content of column A

If column D contains the word fool -> value should be replaced with content of column B

A	B	C	D	E
x	1	x	1	bar
y	3	y	3	bar

How can I create this table?

Answer 1

We can use np.where here:

df["C"] = np.where(df["C"] == "test", df["A"], df["C"])
df["D"] = np.where(df["D"] == "fool", df["B"], df["D"])