CODEWITHSUNDEEP
pythonpandas
user3476463
user3476463

Reputation: 4575

Append records to bottom of dataframe

I have two dataframes like the ones sampled below. I'm trying to append the records from one of the dataframes to the bottom of the first. So the final data frame should only have two columns. Instead I seem to be appending the columns from one dataframe on to the right side of the first. Does anyone see what I'm doing wrong?

Code:

appendDf=df1.append(df2)


df1

    28343  \
0   42267   
1  157180   
2  186320   

  https://s.m.com/is/ime/M/ts/mized/5_fpx.tif  
0  https://sl.com/is/i/M/...                                  
1  https://sl.com/is/i/M/…                                  
2  https://sl.com/is/im/M/... 


df2

    454  \
0   223   
1  155   
2  334  

  https://s.m.com/is/ime/M/ts/mized/5.tif  
0  https://slret.com/is/i/M/...                                  
1  https://slfdsd.com/is/i/M/…                                  
2  https://slfd.com/is/im/M/... 


appendDf.head()

28343   https://s.m.com/is/ime/M/ts/mized/5_fpx.tif 454      https://s.m.com/is/ime/M/ts/mized/5.tif

Upvotes: 0

Views: 5126

Answers (1)

rahlf23
rahlf23

Reputation: 9019

Your DataFrames do not seem to have column headers (I imagine the first row of your data is being used as the column headers), which is likely the root of your issue. When you append the second DataFrame, the program doesn't know which columns the data correspond to, so it adds them as new columns. See the following example:

import pandas as pd

df1 = pd.DataFrame([[28343, 'http://link1'], [42267, 'http://link2'],
    [157180, 'http://link3'], [186320, 'http://link4']], columns=['ID','Link'])

df2 = pd.DataFrame([[454, 'http://link5'], [223, 'http://link6'],
    [155, 'http://link7'], [334, 'http://link8']])

appendedDF = df1.append(df2)

Yields:

         ID          Link      0             1
0   28343.0  http://link1    NaN           NaN
1   42267.0  http://link2    NaN           NaN
2  157180.0  http://link3    NaN           NaN
3  186320.0  http://link4    NaN           NaN
0       NaN           NaN  454.0  http://link5
1       NaN           NaN  223.0  http://link6
2       NaN           NaN  155.0  http://link7
3       NaN           NaN  334.0  http://link8

Correct implementation:

import pandas as pd

df1 = pd.DataFrame([[28343, 'http://link1'], [42267, 'http://link2'],
    [157180, 'http://link3'], [186320, 'http://link4']], columns=['ID','Link'])

df2 = pd.DataFrame([[454, 'http://link5'], [223, 'http://link6'],
    [155, 'http://link7'], [334, 'http://link8']], columns=['ID','Link'])

appendedDF = df1.append(df2).reset_index(drop=True)

Yields:

       ID          Link
0   28343  http://link1
1   42267  http://link2
2  157180  http://link3
3  186320  http://link4
4     454  http://link5
5     223  http://link6
6     155  http://link7
7     334  http://link8

Upvotes: 1

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