How to filter dataframe?

Question

Python

Let's say I have multiple columns in a dataframe. Two columns can contain the same values ​​on the same lines.
Question: what function is needed to filter these lines?
Example.
Before filtering:
After filtering:

Answer 1

On a tip Ilya :
gist

screenshot

Answer 2

If you need to include all columns then:

df = pd.DataFrame()
df[df.nunique(axis=1) == 1]

if only on selected columns then:

subset = [0, 1]
df[df[subset].nunique(axis=1) == 1]