刪除 CSV 文件中的行正在添加額外的行

Question

我正在處理一項編碼任務，其中應用程序的要求之一是能夠刪除 CSV 文件中感興趣的行。 當我嘗試刪除由鍵（名稱）標識的行時，它不僅會刪除該行，還會將我的第一行的多個副本添加到我的 CSV 文件中。 我似乎無法弄清楚為什么要添加這些重復的行。 任何幫助表示贊賞。

供參考：景點是csv文件復制到的字典列表

刪除 function 如下

name = entername()

with open('boston.csv', 'r') as csv_read:
    reader = csv.reader(csv_read)
    for row in reader:
        attractions.append(row)
        for field in row:
            if field == name:
               attractions.remove(row)

with open('boston.csv', 'w') as csv_write:
    writer = csv.writer(csv_write)
    writer.writerows(attractions)

而我之前的 CSV 文件看起來像這樣：

Short Name,Name,Category,URL,Lat,Lon,Color
harvard,Harvard University,university,https://www.harvard.edu/,42.373032,-71.116661,green
mit,Massachusetts Institute of Technology,University,https://www.mit.edu/,42.360092,-71.094162,green
science,Museum of Science,Tourism,https://www.mos.org/,42.36932,-71.07151,green
children,Boston Children's Museum,Tourism,https://bostonchildrensmuseum.org/,42.3531,-71.04998,green

但結果是：

Short Name,Name,Category,URL,Lat,Lon,Color
Short Name,Name,Category,URL,Lat,Lon,Color
Short Name,Name,Category,URL,Lat,Lon,Color
Short Name,Name,Category,URL,Lat,Lon,Color
Short Name,Name,Category,URL,Lat,Lon,Color
harvard,Harvard University,university,https://www.harvard.edu/,42.373032,-71.116661,green
science,Museum of Science,Tourism,https://www.mos.org/,42.36932,-71.07151,green
children,Boston Children's Museum,Tourism,https://bostonchildrensmuseum.org/,42.3531,-71.04998,green

Answer 1

我已經運行了你的代碼，它似乎可以工作。

我將其修改為不覆蓋輸入文件（這在調試時非常有用），在刪除一行時打印一條消息，並對名稱進行硬編碼（同樣，僅用於調試）：

import csv

name = 'Harvard University'

attractions = []
with open('boston.csv', 'r') as csv_read:
    reader = csv.reader(csv_read)
    for row in reader:
        attractions.append(row)
        for field in row:
            if field == name:
                print(f'{field} matches {name}, removing {row}')
                attractions.remove(row)

with open('output.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerows(attractions)

當我運行它時，我看到這些調試打印消息：

Harvard University matches Harvard University, removing ['harvard', 'Harvard University', 'university', 'https://www.harvard.edu/', '42.373032', '-71.116661', 'green']

這是我的output.csv ：

Short Name,Name,Category,URL,Lat,Lon,Color
mit,Massachusetts Institute of Technology,University,https://www.mit.edu/,42.360092,-71.094162,green
science,Museum of Science,Tourism,https://www.mos.org/,42.36932,-71.07151,green
children,Boston Children's Museum,Tourism,https://bostonchildrensmuseum.org/,42.3531,-71.04998,green

當我將 name 更改為name = 'Tourism'時，這對您的邏輯有效（即使它不是您想要的/不打算的），它仍然會按照您的預期進行，刪除Tourism在Category中的兩行場地：

...
name = 'Tourism'

attractions = []
...

Tourism matches Tourism, removing ['science', 'Museum of Science', 'Tourism', 'https://www.mos.org/', '42.36932', '-71.07151', 'green']
Tourism matches Tourism, removing ['children', "Boston Children's Museum", 'Tourism', 'https://bostonchildrensmuseum.org/', '42.3531', '-71.04998', 'green']

Short Name,Name,Category,URL,Lat,Lon,Color
harvard,Harvard University,university,https://www.harvard.edu/,42.373032,-71.116661,green
mit,Massachusetts Institute of Technology,University,https://www.mit.edu/,42.360092,-71.094162,green

Answer 2

有一個純 python convtools庫，它在后台生成代碼並提供大量數據處理原語：

from convtools import conversion as c
from convtools.contrib.tables import Table

name = entername()

table = Table.from_csv("boston.csv")  # pass header=True if it's there
columns = table.columns
table.filter(
    c.not_(
        c.or_(*(c.col(column_name) == name for column_name in columns))
        if len(columns) > 1
        else c.col(columns[0]) == name
    )
).into_csv("boston_output.csv")