Pandas: Merge datasets and check uniqueness
69. Merge Datasets and Check Uniqueness
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
For more Practice: Solve these Related Problems:
- Write a Pandas program to merge two DataFrames on a common key and then check if the key is unique in both datasets.
- Write a Pandas program to perform a merge and then identify duplicate merge keys by comparing the resulting DataFrame's index.
- Write a Pandas program to merge two DataFrames with a one-to-many relationship and then validate the merge by counting rows.
- Write a Pandas program to merge datasets and then output the number of unique keys from each side to confirm one-to-one matching.
Python-Pandas Code Editor:
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