Python。代码在 csv 文件中每行后留下空白行

Question

为什么代码不仅删除 WinningRows，还删除 csv 标题行并在每行后留下空白行？如何修复它？我只需要删除winningRows，不需要空白行。

def generate():
    global winningRows
    filename = enterFile()

    noOfWinners = 5
    winningNumbers = []
    while len(winningNumbers) < noOfWinners:
        luckyNumber = random.randint(1, totalEntries)
        if luckyNumber not in winningNumbers:
            winningNumbers.append(luckyNumber)

    with open(filename, newline="") as entriesCSV:
        entriesDict = csv.DictReader(entriesCSV,dialect="excel")
        allRows = [row for row in entriesDict]
        winningRows = [row for row in allRows if int(row["#"]) in winningNumbers]
        nonWinningRows = [row for row in allRows if int(row["#"]) not in winningNumbers]
        for row in winningRows:
            winnerName = row["Name"]
            winnerID = row["ID"]
            winnerEmail = row["Email"]
            print(f"The winner is {winnerName}, ID {winnerID}, email {winnerEmail}")

        csv.DictWriter(open(filename, "w"), fieldnames=["#", "Name", "ID", "Email"]).writeheader()
        csv.DictWriter(open(filename, "w"), fieldnames=["#", "Name", "ID", "Email"]).writerows(nonWinningRows)

csv before running the code

csv after running the code

看来这有效:

with open(filename, newline='\n') as entriesCSV:
    entriesDict = csv.DictReader(entriesCSV,dialect="excel")
    allRows = [row for row in entriesDict]
    winningRows = [row for row in allRows if int(row["#"]) in winningNumbers]
    nonWinningRows = [row for row in allRows if int(row["#"]) not in winningNumbers]
    for row in winningRows:
        winnerName = row["Name"]
        winnerID = row["ID"]
        winnerEmail = row["Email"]
        print(f"The winner is {winnerName}, ID {winnerID}, email {winnerEmail}")

with open(filename, "w", newline='\n') as entriesCSV:
    writer = csv.DictWriter(entriesCSV, fieldnames=["#", "Name", "ID", "Email"])
    writer.writeheader()
    writer.writerows(nonWinningRows)

但在这种情况下，我打开文件两次，对吧？

Answer 1

看起来您使用的是 Windows。将 newline 参数添加到您的 open 函数中。

with open(filename, "w", newline='\n') as fp:
    writer = csv.DictWriter(fp, fieldnames=["#", "Name", "ID", "Email"])
    writer.writeheader()
    writer.writerows(nonWinningRows)