﻿ Pandas: Merge datasets and check uniqueness - w3resource

# Pandas: Merge datasets and check uniqueness

## Pandas: DataFrame Exercise-69 with Solution

Write a Pandas program to merge datasets and check uniqueness.

Sample Solution :

Python Code :

``````import pandas as pd
df = pd.DataFrame({
'Name': ['Alberto Franco','Gino Mcneill','Ryan Parkes', 'Eesha Hinton', 'Syed Wharton'],
'Date_Of_Birth ': ['17/05/2002','16/02/1999','25/09/1998','11/05/2002','15/09/1997'],
'Age': [18.5, 21.2, 22.5, 22, 23]
})
print("Original DataFrame:")
print(df)
df1 = df.copy(deep = True)
df = df.drop([0, 1])
df1 = df1.drop([2])
print("\nNew DataFrames:")
print(df)
print(df1)
print('\n"one_to_one”: check if merge keys are unique in both left and right datasets:"')
df_one_to_one = pd.merge(df, df1, validate = "one_to_one")
print(df_one_to_one)
print('\n"one_to_many” or “1:m”: check if merge keys are unique in left dataset:')
df_one_to_many = pd.merge(df, df1, validate = "one_to_many")
print(df_one_to_many)
print('“many_to_one” or “m:1”: check if merge keys are unique in right dataset:')
df_many_to_one = pd.merge(df, df1, validate = "many_to_one")
print(df_many_to_one)
``````

Sample Output:

```Original DataFrame:
Name Date_Of_Birth    Age
0  Alberto Franco     17/05/2002  18.5
1    Gino Mcneill     16/02/1999  21.2
2     Ryan Parkes     25/09/1998  22.5
3    Eesha Hinton     11/05/2002  22.0
4    Syed Wharton     15/09/1997  23.0

New DataFrames:
Name Date_Of_Birth    Age
2   Ryan Parkes     25/09/1998  22.5
3  Eesha Hinton     11/05/2002  22.0
4  Syed Wharton     15/09/1997  23.0
Name Date_Of_Birth    Age
0  Alberto Franco     17/05/2002  18.5
1    Gino Mcneill     16/02/1999  21.2
3    Eesha Hinton     11/05/2002  22.0
4    Syed Wharton     15/09/1997  23.0

"one_to_one”: check if merge keys are unique in both left and right datasets:"
Name Date_Of_Birth    Age
0  Eesha Hinton     11/05/2002  22.0
1  Syed Wharton     15/09/1997  23.0

"one_to_many” or “1:m”: check if merge keys are unique in left dataset:
Name Date_Of_Birth    Age
0  Eesha Hinton     11/05/2002  22.0
1  Syed Wharton     15/09/1997  23.0
“many_to_one” or “m:1”: check if merge keys are unique in right dataset:
Name Date_Of_Birth    Age
0  Eesha Hinton     11/05/2002  22.0
1  Syed Wharton     15/09/1997  23.0
```

Python-Pandas Code Editor:

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