Unable to convert into float

Hi,

I get the below error while working on the dataframe I am unable to proceed further. Kindly help me what needs to be done to move further on plotting.
!

The below is the google colab link which i was working
https://colab.research.google.com/drive/1yEBaAedLuu51K8zo5rC6I2_vVHvL9o9q#scrollTo=iL36w7GYfNwQ

Please give access to anyone for the notebook.
Not able to access.

The given string has a colon (:) symbol, which cannot be directly converted into a float value.
Please try using the following:

float(string.split(':')[0])