How to retain the dates while removing punctuation for a string column in pandas

See more:

Python

I have a string column which consists of various information from sentences to dates with punctuation's. When i remove punctuation, the dates are converting to text. Please let me know how to retain the dates.

Sample Input :

Column-1 

meet BM zaheer sir and converted 3 sme tiny 
Met BM Bhupesh kumar and Jayakrishnan sir
01-12-2017
MET BM BEENA - 9895580771
MET CHIEF - 9446486084
05-12-2017
05-12-2017
05-12-2017
Bm not available.
done
Branch meeting

Output :

Column-1 
meet BM zaheer sir and converted 3 sme tiny 
Met BM Bhupesh kumar and Jayakrishnan sir
43070
MET BM BEENA 9895580771
MET CHIEF 9446486084
43074
43074
43074
Bm not available
done
Branch meeting

What I have tried:

df['column-1'] = df['column-1'].str.replace('[^\w\s]','')
 df['column-1'].head()


 df = df.apply(lambda x: x.str.strip()).replace('', np.nan)

 null_columns=df.columns[df.isnull().any()]
 print(df[df["column-1"].isnull()][null_columns])

 import numpy as np
 df = df.replace(np.nan, 'null', regex=True)