使用创建嵌套dictcsv.DictRead

Question

我使用的是python csv module，我有一个CSV，有3列，Item，Part，Category。在

我想创建一个dict，将所有类别组合起来，然后用项目：零件。在

例如：

512 SSD SATA,42-000153,Hardware
5M DisplayPort 1.2 Cable,42-000135,Cable
90W AC Adapter,42-000146,Adapter
4 port USB hub,42-000126,Adapter

我得到的结果是：

^{pr2}$

这几乎让我想到了：

def build_dict(source_file):
    projects = defaultdict(dict)
    headers = ['Product', 'Part Number', 'Category']
    with open(source_file, 'rb') as fp:
        reader = csv.DictReader(fp, fieldnames=headers, dialect='excel',
                                skipinitialspace=True)
        for rowdict in reader:
            if None in rowdict:
                del rowdict[None]
            category = rowdict.pop("Category")
            projects[category] = rowdict
        return dict(projects)

source_file = 'test.csv'

我要找的结果是：

mydict = {
    Hardware:{512 SSD SATA:42-000153},
    Cable:{5M DisplayPort 1.2 Cable,42-000135},
    Adapter:{90W AC Adapter:42-000146,4 port USB hub:42-000126}
    }

请帮忙！在

Answer 1

我将利用Python的内置功能来实现：

import csv
from collections import defaultdict

mydict = defaultdict(dict)
with open('inventory.csv', 'rb') as inf:
    for row in csv.DictReader(inf, fieldnames=['Product', 'Part Number', 
                                               'Category']):
        mydict[row['Category']][row['Product']] = row['Part Number']

import json  # for pretty-printing result
print(json.dumps(mydict, indent=4))

输出：

^{pr2}$

FWIW，您也可以这样做，这需要更多的代码行，但会使内部循环中发生的事情更具可读性。结果是一样的。注意它使用csv.reader而不是csv.DictReader。在

import csv
from collections import defaultdict
from collections import namedtuple

Record = namedtuple('Record', ['product', 'part_number', 'category'])

mydict = defaultdict(dict)
with open('inventory.csv', 'rb') as inf:
    for rec in map(Record._make, csv.reader(inf)):
        mydict[rec.category][rec.product] = rec.part_number  # more readable

Answer 2

这可能有用。在

import csv
import sys

f = open(sys.argv[1], 'rt')

ret = {}
try:
    reader = csv.reader(f)
    for row in reader:
        ret[row[-1]]={" ".join(row[0:2]):row[-2]}
finally:
    f.close()
print str(ret)

Answer 3

只需更改defaultdict以为每个项构建一个列表，您的代码将再次工作。在

def build_dict(source_file):
    projects = defaultdict(list)
    headers = ['Product', 'Part Number', 'Category']
    with open(source_file, 'r') as fp:
        reader = csv.DictReader(fp, fieldnames=headers, dialect='excel',
                                skipinitialspace=True)
        for rowdict in reader:
            if None in rowdict:
                del rowdict[None]
                continue
            category = rowdict.pop("Category")
            projects[category].append(rowdict)
        return dict(projects)

source_file = 'test.csv'

输出：

^{pr2}$

使用json pretty print（感谢martineau）

{
    "Cable": [
        {
            "Part Number": "42-000135",
            "Product": "5M DisplayPort 1.2 Cable"
        }
    ],
    "Adapter": [
        {
            "Part Number": "42-000146",
            "Product": "90W AC Adapter"
        },
        {
            "Part Number": "42-000126",
            "Product": "4 port USB hub"
        }
    ],
    "Hardware": [
        {
            "Part Number": "42-000153",
            "Product": "512 SSD SATA"
        }
    ]
}