python求众数问题实例

list_num = []list_num_count = 0dict_num ={}#从文件读入,文件第一行为集合中元素的个数,以后每一行为一个元素list_num_count = int(open('input.txt','r').readline())for line_num, line in enumerate(open("input.txt",'r')):  if line_num > 0:    list_num += line.split()#将读到的元素加入的字典中for item in list_num:  if dict_num.has_key(item):    dict_num[item] += 1  else:    dict_num.setdefault(item,1)  pass#找到出现次数最多的那个数,找到重数dict_sort_by_top = {}top_value = 0for valus in dict_num.itervalues():  if valus> top_value:    top_value = valus  pass#根据重数找到众数...这是因为考虑到可能有多个元素有相同多的重数the_pop_num = 0the_pop_num_count = 0for keys,values in dict_num.iteritems():  if values == top_value:    print 'the pop num is %s,and the appear num is %s' % (keys,values)    the_pop_num = keys    the_pop_num_count = values#输出到文件,第一行为从数,第二行为重数write_line = '%s/n%s' %(the_pop_num, the_pop_num_count)open("output.txt",'w').write(write_line)

811372372459937

the pop num is 37,and the appear num is 3