pandas.concat() function in Python

01 Oct, 2020
pandas.concat() function does all the heavy lifting of performing concatenation operations along with an axis od Pandas objects while performing optional set logic (union or intersection) of the indexes (if any) on the other axes.
Syntax: concat(objs, axis, join, ignore_index, keys, levels, names, verify_integrity, sort, copy)
Parameters:
objs: Series or DataFrame objects
axis: axis to concatenate along; default = 0
join: way to handle indexes on other axis; default = ‘outer’
ignore_index: if True, do not use the index values along the concatenation axis; default = False
keys: sequence to add an identifier to the result indexes; default = None
levels: specific levels (unique values) to use for constructing a MultiIndex; default = None
names: names for the levels in the resulting hierarchical index; default = None
verify_integrity: check whether the new concatenated axis contains duplicates; default = False
sort: sort non-concatenation axis if it is not already aligned when join is ‘outer’; default = False
copy: if False, do not copy data unnecessarily; default = True
Returns: type of objs (Series of DataFrame)
Example 1: Concatenating 2 Series with default parameters.
Python3
# importing the moduleimport pandas as pd  # creating the Seriesseries1 = pd.Series([1, 2, 3])display('series1:', series1)series2 = pd.Series(['A', 'B', 'C'])display('series2:', series2)  # concatenatingdisplay('After concatenating:')display(pd.concat([series1, series2]))
Output:
Example 2: Concatenating 2 series horizontally with index = 1
Python3
# importing the moduleimport pandas as pd  # creating the Seriesseries1 = pd.Series([1, 2, 3])display('series1:', series1)series2 = pd.Series(['A', 'B', 'C'])display('series2:', series2)  # concatenatingdisplay('After concatenating:')display(pd.concat([series1, series2],                   axis = 1))
Output:
Example 3: Concatenating 2 DataFrames and assigning keys.
Python3
# importing the moduleimport pandas as pd  # creating the DataFramesdf1 = pd.DataFrame({'A': ['A0', 'A1', 'A2', 'A3'],                     'B': ['B0', 'B1', 'B2', 'B3']})display('df1:', df1)df2 = pd.DataFrame({'A': ['A4', 'A5', 'A6', 'A7'],                     'B': ['B4', 'B5', 'B6', 'B7']})display('df2:', df2)  # concatenatingdisplay('After concatenating:')display(pd.concat([df1, df2],                   keys = ['key1', 'key2']))
Output:
Example 4: Concatenating 2 DataFrames horizontally with axis = 1.
Python3
# importing the moduleimport pandas as pd  # creating the DataFramesdf1 = pd.DataFrame({'A': ['A0', 'A1', 'A2', 'A3'],                     'B': ['B0', 'B1', 'B2', 'B3']})display('df1:', df1)df2 = pd.DataFrame({'C': ['C0', 'C1', 'C2', 'C3'],                     'D': ['D0', 'D1', 'D2', 'D3']})display('df2:', df2)  # concatenatingdisplay('After concatenating:')display(pd.concat([df1, df2],                  axis = 1))
Output:
Example 5: Concatenating 2 DataFrames with ignore_index = True so that new index values are displayed in the concatenated DataFrame.
Python3
# importing the moduleimport pandas as pd  # creating the DataFramesdf1 = pd.DataFrame({'A': ['A0', 'A1', 'A2', 'A3'],                     'B': ['B0', 'B1', 'B2', 'B3']})display('df1:', df1)df2 = pd.DataFrame({'A': ['A4', 'A5', 'A6', 'A7'],                     'B': ['B4', 'B5', 'B6', 'B7']})display('df2:', df2)  # concatenatingdisplay('After concatenating:')display(pd.concat([df1, df2],                   ignore_index = True))
Output:
Example 6: Concatenating a DataFrame with a Series.
Python3
# importing the moduleimport pandas as pd  # creating the DataFramedf = pd.DataFrame({'A': ['A0', 'A1', 'A2', 'A3'],                     'B': ['B0', 'B1', 'B2', 'B3']})display('df:', df1)# creating the Seriesseries = pd.Series([1, 2, 3, 4])display('series:', series)  # concatenatingdisplay('After concatenating:')display(pd.concat([df, series],                  axis = 1))
Output:
Python pandas-dataFrame-methods
Python-pandas
Python
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.
Python Dictionary
Different ways to create Pandas Dataframe
Enumerate() in Python
Read a file line by line in Python
Python String | replace()
How to Install PIP on Windows ?
*args and **kwargs in Python
Python Classes and Objects
Iterate over a list in Python
Python OOPs Concepts