How to append a list to dataframe without using column names?

Question

I want to append a list of four prices [1, 2, 3, 4] to an already existing dataframe using the DataFrame.append(), the already existing dataframe has four columns.

Using this

dataframe = pd.DataFrame(columns=["open", "high", "low", "close"],
                         data = [[1, 2, 3, 4]])

Creates the dataframe

   open  high  low  close
0     1     2    3      4

Then I want to append some lists like this:

dataframe = dataframe.append([[5, 6, 7, 8]],
                             ignore_index =True)

Gives the output

   open  high  low  close    0    1    2    3
0   1.0   2.0  3.0    4.0  NaN  NaN  NaN  NaN
1   NaN   NaN  NaN    NaN  5.0  6.0  7.0  8.0

While I want the list to be appended in continuation to the dataframe, is there a way to do this without using the column names, only the list of four prices?

Solution 1

You can do something like

df.loc[len(df)] = [1, 2, 3, 4]

Solution 2

if you will be adding more than one row, you should use the concat function. Which will require you to add the new data in a DataFrame first.

df3 = pd.concat([df1, df2], ignore_index=True)

Read more in the docs here.

Comments

[Slayer]

I think OP wants to append a list to a dataframe. Here pd.concat will concatenate two dataframes.

[mostafazh]

@Prerit I know, I also saw that he said "then I want to append some lists like this", keyword lists.

[Slayer]

Yea, totally missed the "some" word. My bad. He need to convert the list of list to a dataframe and concatenate.

[Mohd]

How about if the added row is not complete, df.loc[len(df)] = [1, 2, 3] , which would result in size mismatch?

[Christian Vincenzo Traina]

The output is like the OP one