I want to convert my columns to multiple array in such a way that each row has values from same date
My data:
Date Value
2006-12-11 816.2
2006-12-11 816.2
2006-12-11 816.2
2006-12-12 848.2
2006-12-12 849.0
2006-12-13 885.6
2006-12-13 887.0
2006-12-13 885.2
2006-12-13 882.0
2006-12-13 885.0
Expected output:
[[816.2, 816.2, 816.2]
[848.2, 849.0]
[885.6, 887.0, 885.2, 882.0, 885.0]]
You can use groupby with numpy.array:
import numpy as np:
df.Value.groupby(df.Date).apply(np.array).values
Example:
df = pd.DataFrame({
"Date": ['2006-12-11', '2006-12-11', '2006-12-11', '2006-12-12', '2006-12-12'],
'Value': [816.2, 816.2, 816.2, 848.2, 849.0]})
df.Value.groupby(df.Date).apply(np.array).values
array([array([816.2, 816.2, 816.2]), array([848.2, 849. ])], dtype=object)
You can convert values to list:
df.groupby(by=df.Date).agg(lambda x: x.tolist()).values