如何添加標題以從 Python CSV 文件中讀取 output？

Question

我有一個 csv 文件，看起來像這樣：

CSV 文件

我有以下代碼，它讀取 csv 文件，然后可以打印/訪問 CSV 文件中的信息。

import csv

class CsvReader:
    
    with open("Items.csv") as fp:
        reader = csv.reader(fp, delimiter=",", quotechar='"')
        next(reader, None)  # skip the headers
        data_read = [row for row in reader]

    print(data_read[0])

我從印刷品中得到了 output

['1', '5.99$, '1', 'Blueberry Muffin']

我將如何將其格式化為字典，將標題作為鍵，將信息作為元素？

例如，代碼為 output：

{Item #: 1, Price: 5.99, Quantity: 1, Name: Blueberry Muffin}

我在這篇文章中引用並看到了很多相似之處： How do I read and write CSV files with Python?

但找不到更多關於如何以這種方式專門格式化 output 的細節，而不使用諸如 pandas 之類的東西，我不想使用它。

Answer 1

如果您希望將字典鍵作為字段即列，那么您為什么要跳過它們。 這里是簡單的解決方案。

import csv

class CsvReader:
    with open("Item.csv") as fp:
        reader = csv.reader(fp, delimiter=",", quotechar='"')
        fields = next(reader)
        data_read = []
        for row in reader:
            data_read.append(dict(zip(fields, row)))

    print(data_read[0])

首先將列名和 map 與每個行元素一起存儲。

Answer 2

有幾種方法可以做到這一點......而且我同意使用 Pandas 對於讀取簡單文件可能是過大的。 您可能會爭辯說，即使使用csv_reader也是矯枉過正。 :)

無論如何，這里有 3 種變體。 您需要做的就是捕獲標簽並將它們用作字典中的鍵。 意識到下面的方法將為您提供“字典列表”（或 pandas-speak 中的“記錄”類型格式）。 另一種選擇是使用項目編號作為第一個鍵的“字典字典”，但本質上這與列表索引相同......所以大致相同。 您也可以放棄捕獲項目編號，因為這只是結果列表中的索引，但這是細微差別。

您可能還對在最后一個變體中顯示的named tuple中捕獲它們感興趣。 非常容易使用...

# Grocery Reader

import csv
from collections import namedtuple


with open("data.csv") as fp:
    reader = csv.reader(fp, delimiter=",", quotechar='"')
    labels = next(reader, None)  # capture the headers
    result = []
    for row in reader:  # iterate the remaining rows
        pairs = zip(labels, row)
        result.append(dict(pairs))

print(result)

# the above isn't real satisfying as the numeric objects are captured as strings.
# so...
with open("data.csv") as fp:
    reader = csv.reader(fp, delimiter=",", quotechar='"')
    labels = next(reader, None)  # capture the headers
    result = []
    for row in reader:  # iterate the remaining rows
        row[0] = int(row[0])
        row[1] = float(row[1])
        row[2] = int(row[2])
        pairs = zip(labels, row)
        result.append(dict(pairs))

print(result)

with open("data.csv") as fp:
    reader = csv.reader(fp, delimiter=",", quotechar='"')
    labels = next(reader, None)  # capture the headers
    # make lowercase...just for standardization
    labels = [t.lower() for t in labels]
    Grocery = namedtuple('Grocery', labels)
    result = []
    for row in reader:  # iterate the remaining rows
        row[0] = int(row[0])
        row[1] = float(row[1])
        row[2] = int(row[2])
        grocery = Grocery(*row)
        result.append(grocery)

for grocery in result:
    # the below presumes you know the names inside the named tuple...
    print(f'a {grocery.name} costs {grocery.price}')

產量（data.csv 可以推斷）

[{'Item': '1', 'Price': '4.99', 'Qty': '2', 'Name': 'Muffin'}, {'Item': '2', 'Price': '1.25', 'Qty': '6', 'Name': 'Gum'}, {'Item': '3', 'Price': '2.50', 'Qty': '8', 'Name': 'Cookie'}]
[{'Item': 1, 'Price': 4.99, 'Qty': 2, 'Name': 'Muffin'}, {'Item': 2, 'Price': 1.25, 'Qty': 6, 'Name': 'Gum'}, {'Item': 3, 'Price': 2.5, 'Qty': 8, 'Name': 'Cookie'}]
a Muffin costs 4.99
a Gum costs 1.25
a Cookie costs 2.5

Answer 3

從這里使用DictReader csv 。

cat food.csv                                                                                                                                                                                                           
Item #,Price,Quantity,Name
1, 5.99$,1,Blueberry Muffin


import csv
with open('food.csv') as csv_file:
    reader = csv.DictReader(csv_file,delimiter=",", quotechar='"')
    for row in reader:
        print(dict(row))

{'Item #': '1', 'Price': ' 5.99$', 'Quantity': '1', 'Name': 'Blueberry Muffin'}

Answer 4

使用csv.DictReader並跳過第一行：

import csv

with open("tmp/1.csv", "r") as f:
    reader = csv.DictReader(
        f, fieldnames=["Item", "Price", "Quantity", "Name"]
    )

    # skipping existing header
    it = iter(reader)
    next(it, None)

    for row in it:
        print(row)