Merge & Join List of pandas DataFrames in Python (Example Code)
In this article you’ll learn how to combine a list of multiple pandas DataFrames in the Python programming language.
Setting up the Example
import pandas as pd # Import pandas library to Python |
import pandas as pd # Import pandas library to Python
df1 = pd.DataFrame({"ID":range(1, 6), # Construct three DataFrames "A":range(11, 16), "B":["g", "x", "g", "d", "f"]}) print(df1) # ID A B # 0 1 11 g # 1 2 12 x # 2 3 13 g # 3 4 14 d # 4 5 15 f |
df1 = pd.DataFrame({"ID":range(1, 6), # Construct three DataFrames "A":range(11, 16), "B":["g", "x", "g", "d", "f"]}) print(df1) # ID A B # 0 1 11 g # 1 2 12 x # 2 3 13 g # 3 4 14 d # 4 5 15 f
df2 = pd.DataFrame({"ID":range(3, 8), "C":["a", "y", "s", "x", "a"], "D":range(12, 2, - 2)}) print(df2) # ID C D # 0 3 a 12 # 1 4 y 10 # 2 5 s 8 # 3 6 x 6 # 4 7 a 4 |
df2 = pd.DataFrame({"ID":range(3, 8), "C":["a", "y", "s", "x", "a"], "D":range(12, 2, - 2)}) print(df2) # ID C D # 0 3 a 12 # 1 4 y 10 # 2 5 s 8 # 3 6 x 6 # 4 7 a 4
df3 = pd.DataFrame({"ID":range(2, 10), "E":range(10, 2, - 1), "F":range(9, 1, - 1)}) print(df3) # ID E F # 0 2 10 9 # 1 3 9 8 # 2 4 8 7 # 3 5 7 6 # 4 6 6 5 # 5 7 5 4 # 6 8 4 3 # 7 9 3 2 |
df3 = pd.DataFrame({"ID":range(2, 10), "E":range(10, 2, - 1), "F":range(9, 1, - 1)}) print(df3) # ID E F # 0 2 10 9 # 1 3 9 8 # 2 4 8 7 # 3 5 7 6 # 4 6 6 5 # 5 7 5 4 # 6 8 4 3 # 7 9 3 2
my_list = [df1, df2, df3] # Construct list object |
my_list = [df1, df2, df3] # Construct list object
Example: Joining Three pandas DataFrames in List in Python
from functools import reduce # Loading reduce function |
from functools import reduce # Loading reduce function
df_joined = reduce(lambda left, right: # Merge multiple DataFrames in list pd.merge(left , right, on = ["ID"]), my_list) print(df_joined) # ID A B C D E F # 0 3 13 g a 12 9 8 # 1 4 14 d y 10 8 7 # 2 5 15 f s 8 7 6 |
df_joined = reduce(lambda left, right: # Merge multiple DataFrames in list pd.merge(left , right, on = ["ID"]), my_list) print(df_joined) # ID A B C D E F # 0 3 13 g a 12 9 8 # 1 4 14 d y 10 8 7 # 2 5 15 f s 8 7 6
Related Tutorials
Have a look at the following list of Python programming tutorials. They discuss topics such as variables, data conversion, and lists.