miss numpy package

[zhang787jun]

🐛 Bug Description

qlib/qlib/contrib/backtest/position.py /

161        cash = pd.Series(dtype=np.float)

NameError: name 'np' is not defined

To Reproduce

Steps to reproduce the behavior:

1. import numpy at head

import numpy as np 

Expected Behavior

Screenshot

Environment

Note: User could run cd scripts && python collect_info.py all under project directory to get system information
and paste them here directly.

• Qlib version:
• Python version:
• OS (Windows, Linux, MacOS):
• Commit number (optional, please provide it if you are using the dev version):

Additional Notes

[you-n-g]

Hi, @zhang787jun
Thanks so much for submitting this issue.
Would you mind sending a PR to fix this issue and become one of the contributors of Qlib!