Pandas Joining and merging DataFrame : Exercises, Practice, Solution

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Pandas Joining and merging DataFrame [ 15 exercises with solution]

1. Write a Pandas program to join the two given dataframes along rows and assign all data.
Test Data:

student_data1:
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

student_data2:
  student_id              name  marks
0         S4  Scarlette Fisher    201
1         S5  Carla Williamson    200
2         S6       Dante Morse    198
3         S7    Kaiser William    219
4         S8   Madeeha Preston    201

2. Write a Pandas program to join the two given dataframes along columns and assign all data.
Test Data:

student_data1:
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

student_data2:
  student_id              name  marks
0         S4  Scarlette Fisher    201
1         S5  Carla Williamson    200
2         S6       Dante Morse    198
3         S7    Kaiser William    219
4         S8   Madeeha Preston    201

3. Write a Pandas program to append rows to an existing DataFrame and display the combined data.
Test Data:

tudent_data1
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

New Row(s)
student_id                  S6
name          Scarlette Fisher
marks                      205
dtype: object

4. Write a Pandas program to append a list of dictioneries or series to a existing DataFrame and display the combined data.
Test Data:

  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

Dictionary:
student_id                  S6
name          Scarlette Fisher
marks                      205
dtype: object

5. Write a Pandas program to join the two given dataframes along rows and merge with another dataframe along the common column id.
Test Data:

student_data1:
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

student_data2:
  student_id              name  marks
0         S4  Scarlette Fisher    201
1         S5  Carla Williamson    200
2         S6       Dante Morse    198
3         S7    Kaiser William    219
4         S8   Madeeha Preston    201

exam_data:
   student_id  exam_id
0          S1       23
1          S2       45
2          S3       12
3          S4       67
4          S5       21
5          S7       55
6          S8       33
7          S9       14
8         S10       56
9         S11       83
10        S12       88
11        S13       12

6. Write a Pandas program to join the two dataframes using the common column of both dataframes.
Test Data:

student_data1:
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

student_data2:
  student_id              name  marks
0         S4  Scarlette Fisher    201
1         S5  Carla Williamson    200
2         S6       Dante Morse    198
3         S7    Kaiser William    219
4         S8   Madeeha Preston    201

7. Write a Pandas program to join the two dataframes with matching records from both sides where available.
Test Data:

student_data1:
  student_id              name  marks
0         S1  Danniella Fenton    200
1         S2      Ryder Storey    210
2         S3      Bryce Jensen    190
3         S4         Ed Bernal    222
4         S5       Kwame Morin    199

student_data2:
  student_id              name  marks
0         S4  Scarlette Fisher    201
1         S5  Carla Williamson    200
2         S6       Dante Morse    198
3         S7    Kaiser William    219
4         S8   Madeeha Preston    201

8. Write a Pandas program to join (left join) the two dataframes using keys from left dataframe only.
Test Data:

data1:
  key1 key2   P   Q
0   K0   K0  P0  Q0
1   K0   K1  P1  Q1
2   K1   K0  P2  Q2
3   K2   K1  P3  Q3

data2:
  key1 key2   R   S
0   K0   K0  R0  S0
1   K1   K0  R1  S1
2   K1   K0  R2  S2
3   K2   K0  R3  S3

9. Write a Pandas program to join two dataframes using keys from right dataframe only.
Test Data:

data1:
  key1 key2   P   Q
0   K0   K0  P0  Q0
1   K0   K1  P1  Q1
2   K1   K0  P2  Q2
3   K2   K1  P3  Q3

data2:
  key1 key2   R   S
0   K0   K0  R0  S0
1   K1   K0  R1  S1
2   K1   K0  R2  S2
3   K2   K0  R3  S3

10. Write a Pandas program to merge two given datasets using multiple join keys.
Test Data:

data1:
  key1 key2   P   Q
0   K0   K0  P0  Q0
1   K0   K1  P1  Q1
2   K1   K0  P2  Q2
3   K2   K1  P3  Q3

data2:
  key1 key2   R   S
0   K0   K0  R0  S0
1   K1   K0  R1  S1
2   K1   K0  R2  S2
3   K2   K0  R3  S3

11. Write a Pandas program to create a new DataFrame based on existing series, using specified argument and override the existing columns names.
Click me to see the sample solution

12. Write a Pandas program to create a combination from two dataframes where a column id combination appears more than once in both dataframes.
Test Data:

data1:
  key1 key2   P   Q
0   K0   K0  P0  Q0
1   K0   K1  P1  Q1
2   K1   K0  P2  Q2
3   K2   K1  P3  Q3

data2:
  key1 key2   R   S
0   K0   K0  R0  S0
1   K1   K0  R1  S1
2   K1   K0  R2  S2
3   K2   K0  R3  S3

13. Write a Pandas program to combine the columns of two potentially differently-indexed DataFrames into a single result DataFrame.
Test Data:

data1:
     A   B
K0  A0  B0
K1  A1  B1
K2  A2  B2

data2:
     C   D
K0  C0  D0
K2  C2  D2
K3  C3  D3

14. Write a Pandas program to merge two given dataframes with different columns.
Test Data:

data1:
  key1 key2   P   Q
0   K0   K0  P0  Q0
1   K0   K1  P1  Q1
2   K1   K0  P2  Q2
3   K2   K1  P3  Q3

data2:
  key1 key2   R   S
0   K0   K0  R0  S0
1   K1   K0  R1  S1
2   K1   K0  R2  S2
3   K2   K0  R3  S3

15. Write a Pandas program to Combine two DataFrame objects by filling null values in one DataFrame with non-null values from other DataFrame.
Test Data:

Original DataFrames:
     A  B
0  NaN  3
1  0.0  4
2  NaN  5

   A    B
0  1  3.0
1  1  NaN
2  3  3.0

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