[SOLVED] How to explode a column

How to explode a column

Not able to use explode from pandas df.

I want to "explode" a named column with named sub columns in a data frame on Jupyter Notebook.

Here is the data frame :

   State or territory  Census population[8][9][a]               
   State or territory         July 1, 2024 (est.)  April 1, 2020
0          California                  39431263.0       39538223
1               Texas                  31290831.0       29145505
2             Florida                  23372215.0       21538187
3            New York                  19867248.0       20201249
4        Pennsylvania                  13078751.0       13002700

I want to explode Census population and then delete April 1 2020 leaving "State or territory" and "July 1, 2024 (est.)"

import pandas as pd

tables1 = pd.read_html("https://en.wikipedia.org/wiki/Fortune_500")
tables2 = pd.read_html(
    "https://en.wikipedia.org/wiki/List_of_U.S._states_and_territories_by_population")

df1 = tables[1]
df2 = tables2[0]

df1copy = df1.drop(["Rank"], axis=1)
df2copy = df2.drop(
    ["Change, 2010–2020[9][a]",
     "House seats[b]",
     "Pop.  per elec. vote (2020)[c]",
     "Pop. per seat (2020)[a]",
     "% US (2020)",
     "% EC (2020)"],
    axis=1)
print(df1copy.head())
print(df2copy.head())
df2.drop(["July 1, 2024 (est.)"], axis=1)
print(df2.head())

Here is the result:

KeyError  Traceback (most recent call last)
  File ~/Library/Python/3.9/lib/python/site-packages/pandas/core/indexes/base.py:3805, in Index.get_loc(self, key)
    3804 try:
 -> 3805     return self._engine.get_loc(casted_key)
    3806 except KeyError as err:
KeyError: 'July 1, 2024 (est.)'

Solution

You need to specify the level of the column index that you want to drop.

Since the date column you want to drop is in level 1 you need to mention it explicitly.

df2.drop(columns=["July 1, 2024 (est.)"], level=1, axis=1)