Question

似乎可以正常工作，问题是，它只返回csv文件的第一行，我在做什么错了？

我正在尝试将一个csv文件导入到我的python代码中，但它仅返回csv文件的第一行

import csv
with open('aapl_price-history-01-09-2019.csv') as csvfile:
    fieldnames = ['Time', 'Open', 'High', 'Low', 'Last', 'Change', 'Volume']
    stockPxReader = csv.DictReader(csvfile)
    stockPxData = {}
    for row in stockPxReader:
        stockPxData = row
    print(stockPxData)

Answer 1

请在此处将stockPxData = {}更改为stockPxData = []，然后将行追加到stockPxData列表。

import csv
with open('aapl_price-history-01-09-2019.csv') as csvfile:
    fieldnames = ['Time', 'Open', 'High', 'Low', 'Last', 'Change',
    'Volume']
    stockPxReader = csv.DictReader(csvfile)
    stockPxData = []
    for row in stockPxReader:
        stockPxData.append(row)
print(stockPxData)

Answer 2

您正在尝试将一项添加到词典中。字典具有“键”：“值”对。您所做的只是在字典中添加“值”。

import csv
with open('aapl_price-history-01-09-2019.csv') as csvfile:
    fieldnames = ['Time', 'Open', 'High', 'Low', 'Last', 'Change', 'Volume']
    stockPxReader = csv.DictReader(csvfile)
    stockPxData = {}
    idx = 0                           # this is to initialize the index counter
    for row in stockPxReader:
        stockPxData[str(idx)] = row   # syntax to assign key value to dict
        idx = idx + 1                 # update index value in the for loop
        print(stockPxData)            # print in the open file handler statement

Answer 3

您正在执行任务：stockPxData = row。这样只会在该变量中存储一个字典。

为了存储所有行，请尝试将它们附加到列表中，例如

stockPxData = []
for row in stockPxReader:
    stockPxData.append(row)

或为每个dict元素定义要存储在dict中的键（这里我将数组中的索引用作键）：

for idx, row in enumerate(stockPxReader):
    stockPxData[str(idx)] = row

csv.DictReader函数仅读取csv文件的第一行

3 个答案: