# Show rows with NaN
df[df.isna().any(axis=1)]
# remove NaNs
df = df.replace(
[np.inf, -np.inf], np.nan
).dropna()
# Alternatively go by row
# Get NA subjects
na_subjects_index = df[df["Initials"].isna()].index
# Remove NA subjects
df.drop(index=na_subjects_index, axis=0, inplace=True)