how to check for duplicates in pandas code example

Example 1: find duplicated rows with respect to multiple columns pandas

df = df[df.duplicated(subset=['val1','val2'], keep=False)]
print (df)
   id  val1  val2
0   1   1.1   2.2
1   1   1.1   2.2
3   3   8.8   6.2
4   4   1.1   2.2
5   5   8.8   6.2

Example 2: count how many duplicates python pandas

df.duplicated(subset='one', keep='first').sum()

Example 3: count duplicates in one column pandas

df.pivot_table(index=['DataFrame Column'], aggfunc='size')