I am trying to delete the first few characters of each row in a dataframe and getting an error. I am quite new to pandas, trying to learn though. I don't quite get what the warning means, and why it is showing up.
The problem:
As an example:
import pandas as pd
df = {
'Heading':['Line 1', 'Line 2','Line 3'],
'Text' :['blabla useful info', 'xyxyxy useful info', 'abcabc useful info']
}
df = pd.DataFrame(d)
I want to remove the first 7 characters because I know that after that the useful info starts. To do this, I am using the solution described here:
df['Text'] = df['Text'].str[7:]
However, when doing this, it results in a SettingWithCopyWarning, like this:
SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead
This error does not occur whenever I filter the dataframe like this just before tying to slice:
df = df[df['Text'].str.contains('stuff')]
df['Text'] = df['Text'].str[7:]
Some background info
I am getting the dataframe from a list of other dataframes. This list was made by filtering a very large dataframe with different information in a specific row. I wanted to split this large frame based on the type of information in this specific row, and then apply data edits to the information.
So the list contains:
[dataframe with info x,
dataframe with info y,
dataframe with info z]
I want to do a certain thing with info x, another thing with info y and a third thing with info z. This can probably be done with combining the groupby() and apply() functions as well, so if that is easier or more convenient, enlighten me!
