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DataFrame.insert( loc , column , value , allow_duplicates=False ) -
Insert column into DataFrame at specified location.
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Raises a ValueError if column is already contained in the DataFrame,unless allow_duplicates is set to True.
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Insert a column of data at the specified location. If a column already exists in the dataframe, set allow_duplicates to true to insert the specified column.
Parameters: loc : int
Insertion index. Must verify 0 <= loc <= len(columns) which column to insert
column : string, number, or hashable object
label of the inserted column label of the inserted column
value : int, Series, or array-like
allow_duplicates : bool, optional Boolean type, optional
An example is as follows:
import numpy as np
import pandas as pd
# A = np.array([[1, 1], [1, 2], [1, 3]])
# print(np.shape(A))
df = pd.DataFrame(np.random.randint(1, 10, (6, 4)), index=None, columns=list('ABCD'))
df['E'] = pd.Series([1, 1, 1, 1, 1, 1])
s = pd.Series([1, 1, 1, 1, 1, 1])
df.insert(1, 'X', s)
print(df)
operation result:
A X B C D E
0 7 1 6 6 1 1
1 6 1 7 3 8 1
2 8 1 3 7 1 1
3 3 1 5 4 9 1
4 6 1 9 6 5 1
5 6 1 5 6 5 1