def sellcommodity(self):
p = int(input('请输入商品编号：'))
if p in types:
print('ok')
else:
print('no')
sellcommodity() # 输入1 no 输入2 ok
str.find(sub)查找字符串内是否包含子字符串sub，如果包含则返回子字符串首字符的索引，否则返回-1
str.find(sub) == 0
判断str是否以sub开头，相当于
str.startswith(sub)
不公用panda，所以直接用列表和字典来写#最终统计后的结果，字典格式products = {}#读取的记录，列表格式records = []#读取文件的每一行，列表格式lines = []#读取文件，将所有内容写入列表recordswith open("productinfo.txt","r") as f:#循环读取while True:line = f.readline()#读到结尾退出循环if not line:break#如果每行的内容结尾有换行符就舍去if line[-1] == '\n':line = line[:-1]#把每行的数据以逗号为标志分割lines = line.split(',')#把分割的数据追加到列表records.append(lines)#遍历读到的结果，将结果经过计算后写入字典productsfor record in records:#每条记录的第一项作为字典的KEY，如果这个KEY在字典中就在基础上增加值if record[0] in products:products[record[0]]['total_sales'] += eval(record[2])products[record[0]]['total_money'] += eval(record[1]) * eval(record[2])#如果这个KEY不在字典，就设置为record原值else:products[record[0]] = {'total_sales':eval(record[2]),'total_money':eval(record[1]) * eval(record[2])}#排序sales=sorted(products.items(), key=lambda x:x[1]['total_sales'])print("最大销量商品编号：", sales[-1][0],"销量：",sales[-1][1]['total_sales'])print("最低销量商品编号：", sales[0][0],"销量：",sales[0][1]['total_sales'])
