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+--- Thread: [Solved] Delete a line in a dataframe using .reset_index() and .drop() (/thread-36497.html)
[Solved] Delete a line in a dataframe using .reset_index() and .drop() - ju21878436312 - Feb-25-2022
Hi out there,
I'd like to delete a line in the dataframe "df_new". Why does it not work? I get the error: "KeyError: '[0] not found in axis".
import pandas as pd
import numpy as np
data = {'x': [0,1, 2,3,4,5,6,7,8],
'y': [60, 23, 24,42,56,10,20,25,13],
'comment': ["false", "true","true","true","true","true","true","true","true"],
}
df = pd.DataFrame(data)
df_new = df.loc[df['comment'] == "true"]
# This works fine
df = df.drop([0])
# This creates an error: KeyError: '[0] not found in axis'
df_new = df_new.drop([0])
print(type(df)) # <class 'pandas.core.frame.DataFrame'>
print(type(df_new)) # <class 'pandas.core.frame.DataFrame'>
RE: Delete a line in a dataframe - deanhystad - Feb-25-2022
Indexing in pandas is not like indexing a list. Deleting a row does not change the index of the trailing rows. In your example df_new doesn't have an index[0].
You filtered out index[0] when when creating df_new. df_new starts at index[1]
You can reset the index using reset_index()
https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.reset_index.html
import pandas as pd
data = {'x': [0,1, 2,3,4,5,6,7,8],
'y': [60, 23, 24,42,56,10,20,25,13],
'comment': ["false", "true","true","true","true","true","true","true","true"],
}
df = pd.DataFrame(data)
df_new = df.loc[df['comment'] == "true"]
print(df_new)
df_new = df_new.reset_index(drop=True)
print(df_new)
df_new = df_new.drop(0)
print(df_new)
RE: Delete a line in a dataframe - ju21878436312 - Feb-25-2022
Thank you very much!
