install itertools

sudo pip3 install more-itertools

# Python code to demonstrate the working of    
# dropwhile()  
  
  
# Function to be passed 
# as an argument 
def is_positive(n): 
    return n > 0 
  
value_list =[5, 6, -8, -4, 2] 
result = list(itertools.dropwhile(is_positive, value_list))  
   
print(result)