Concatenate pandas DataFrame to Existing CSV File in Python (Example Code)

import pandas as pd                             # Import pandas library

import pandas as pd # Import pandas library

my_df = pd.DataFrame({'A':range(0, 5),          # Construct pandas DataFrame in Python
                      'B':['x', 'y', 'x', 'x', 'y'],
                      'C':range(15, 10, - 1)})
print(my_df)
#    A  B   C
# 0  0  x  15
# 1  1  y  14
# 2  2  x  13
# 3  3  x  12
# 4  4  y  11

my_df = pd.DataFrame({'A':range(0, 5), # Construct pandas DataFrame in Python 'B':['x', 'y', 'x', 'x', 'y'], 'C':range(15, 10, - 1)}) print(my_df) # A B C # 0 0 x 15 # 1 1 y 14 # 2 2 x 13 # 3 3 x 12 # 4 4 y 11

my_df.to_csv('my_df.csv', index = False)        # Saving pandas DataFrame as CSV

my_df.to_csv('my_df.csv', index = False) # Saving pandas DataFrame as CSV

my_df_new = pd.DataFrame({'A':range(10, 13),    # Construct another DataFrame
                          'B':['foo', 'bar', 'foo'],
                          'C':range(100, 103)})
print(my_df_new)
#     A    B    C
# 0  10  foo  100
# 1  11  bar  101
# 2  12  foo  102

my_df_new = pd.DataFrame({'A':range(10, 13), # Construct another DataFrame 'B':['foo', 'bar', 'foo'], 'C':range(100, 103)}) print(my_df_new) # A B C # 0 10 foo 100 # 1 11 bar 101 # 2 12 foo 102

my_df_new.to_csv('my_df.csv',                   # Append data at the bottom
                 mode = 'a',
                 header = False,
                 index = False)

my_df_new.to_csv('my_df.csv', # Append data at the bottom mode = 'a', header = False, index = False)