pythonは、リストに最も多く表示されている要素を返します.

lt = ['  ', '  ', '  ', '  ', '  ', '  ', '  ', '  ']
def max_count(lt):
    #       ，            
    d = {}
    #           
    max_key = None
    #     ，           ，        
    for i in lt:
        if i not in d:
            #          
            count = lt.count(i)
            #       
            d[i] = count
            #          
            if count > d.get(max_key, 0):
                max_key = i
    return max_key
print(max_count(lt))

#     
print(max(lt, key=lt.count))

from collections import Counter
c = Counter(lt)
# print(dict(c))
print(c.most_common(1)[0][0])