python编程基础小练习

1、# python编程基础，主要包括python的基本语法，内建数据结构、函数以及文件操作

# 1、读取数据
import csv
f = open('./xiaoqu_data/1xiaoqu_shijiazhuang2.csv', 'r', encoding='UTF-8')
reader = csv.reader(f)
data = []
for row in reader:
    data.append(row)
# 显示data前5行
for i in range(5):
    print(data[i])

# 2、处理数据
# 1）查看小区中共有几种关注数据
guanzhu_list = []
for row in data:
    # 小区关注等级数据
    guanzhu_list.append(int(row[2]))
guanzhu_count = set(guanzhu_list)
print("
小区关注共有%d种数据，分别是：%r" %(len(guanzhu_count),guanzhu_count))

# 2）按小区关注等级将数据集划分为7个子集，并统计每种等级的数量
content_dict = {}
for row in data:
    guanzhu = int(row[2])
    if guanzhu not in content_dict.keys():
        # 用字典保存每个子集
        content_dict[guanzhu] = [row]
    else:
        content_dict[guanzhu].append(row)
for key in content_dict:
    print("
",key,':',len(content_dict[key]))


# 3)计算每个数据集中 元/平方 的均值
mean_list = []
for key,value in content_dict.items():
    sum = 0
    for row in value:
        # 元/平方 是第四列数据
        sum = sum + float(row[3])
    mean_list.append((key, sum/len(value)))
# 打印均值
for item in mean_list:
    print(item[0],":",item[1])
    
f.close()