统计“zifuchuan我是个程序ii”中中文的个数

#!/usr/bin python#encoding:utf8def main():    str = "zifuchuan我是个程序ii"    sum = 0    for i in range(len(str.decode('utf-8'))):         if str.decode('utf-8')[i]<='z':             continue         else:             sum+=1    print sumif __name__ == "__main__":    main()~

有别的什么好方法请不吝赐教 初学者