如何在python中将csv转换为字典? [英] How to convert csv to dictionary of dictionaries in python?

问题描述

我有一个如下所示的CSV文件.我需要使用python将CSV转换成字典.

I have a CSV file shown below.I need to convert CSV to dictionary of dictionaries using python.

 userId movieId rating
1         16    4
1         24    1.5
2         32    4
2         47    4
2         50    4
3        110    4
3        150    3
3        161    4
3        165    3

输出应如下所示

dataset={'1':{'16':4,'24':1.5},
         '2':{'32':4,'47':4,'50':4},
         '3':{'110':4,'150':3,'161':4,'165':3}}

请让我知道如何执行此操作.预先感谢

Please let me know how to do this. Thanks in advance

推荐答案

您正在寻找嵌套词典.在Python中实现perl的自动生存功能(详细说明在

You are looking for nested dictionaries. Implement the perl's autovivification feature in Python (the detailed description is given here). Here is a MWE.

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import csv

class AutoVivification(dict):
    """Implementation of perl's autovivification feature."""
    def __getitem__(self, item):
        try:
            return dict.__getitem__(self, item)
        except KeyError:
            value = self[item] = type(self)()
            return value

def main():
    d = AutoVivification()
    filename = 'test.csv'
    with open(filename, 'r') as f:
        reader = csv.reader(f, delimiter=',')
        next(reader)        # skip the header
        for row in reader:
            d[row[0]][row[1]] = row[2]

    print(d)
    #{'1': {'24': '1.5', '16': '4'}, '3': {'150': '3', '110': '4', '165': '3', '161': '4'}, '2': {'32': '4', '50': '4', '47': '4'}}

if __name__ == '__main__':
    main()

---

test.csv的内容，

---

The content of test.csv,

userId,movieId,rating
1,16,4
1,24,1.5
2,32,4
2,47,4
2,50,4
3,110,4
3,150,3
3,161,4
3,165,3

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