get excel file header and check if valid excel file

Question

I have a very weird situation in which sometimes I will have valid excel and some times like this

so In case of these randoms I will discard and won't process this . So is there any way to do this ?

and 2nd thing how I can print all headers currently I am getting this

df = pd.read_excel(file_name.xlsx , sheet_name=key)
print(df.head()) 

but it's not printing headers