CODEWITHSUNDEEP
pythonpandasdataframe
Filip Eriksson
Filip Eriksson

Reputation: 977

ValueError: Cannot shift with no freq

I have tried to write the following code but I get the error message: "ValueError: Cannot shift with no freq." I have no idea of how to fix it? I tried to google on the error message but couldn't find any case similar to mine.

df is a python pandas dataframe for which I want to create new columns showing the daily change. The code is shown below. How can I fix the code to avoid the value error?

for column_names in df:
        df[column_names+'%-daily'] =df[column_names].pct_change(freq=1).fillna(0)

Upvotes: 1

Views: 7027

Answers (2)

Asclepius
Asclepius

Reputation: 63333

To resolve the error, instead of df.index.shift(), I had to use pd.Series(df.index).shift().

Overall, I used it as below:

df['index_diff'] = (df.index - pd.Series(df.index).shift()).values

Upvotes: 0

Filip Eriksson
Filip Eriksson

Reputation: 977

The problem was that I had date as index. Since only weekdays were shown delta became incorrect. When I changed to period.

for column_names in list(df.columns.values):
        df[column_names+'%-daily'] =df[column_names].pct_change(periods=1).fillna(0)

Upvotes: 1

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