add column using a list at poisition zero pandas code example

Example 1: pandas insert column in the beginning

insert_index = 0
insert_colname = 'new column'
insert_values = [1, 2, 3, 4, 5] # this can be a numpy array too
df.insert(loc=insert_index, column=insert_colname, value=insert_values)

Example 2: add column using a list at poisition zero pandas

df = pd.DataFrame({'B': [1, 2, 3], 'C': [4, 5, 6]})

df
Out: 
   B  C
0  1  4
1  2  5
2  3  6

idx = 0
new_col = [7, 8, 9]  # can be a list, a Series, an array or a scalar   
df.insert(loc=idx, column='A', value=new_col)

df
Out: 
   A  B  C
0  7  1  4
1  8  2  5
2  9  3  6