check for duplicates in pandas code example

Example 1: print duplicates elements in column pandas

mask = df.columnname.duplicated(keep=False)
print (df[mask])

Example 2: python - show repeted values in a column

df = df[df.duplicated(subset=['val1','val2'], keep=False)]

Example 3: how to check for duplicates in a column in python

boolean = df['Student'].duplicated().any() # True