使用 csv 模块和 datetime 模块解析时间戳

Question

我datetime在使用 Python 中的模块时遇到了一些问题。我有来自 csv 文件的数据：

user_id,timestamp

563,0:00:21

671,0:00:26

780,0:00:28

这是我的代码：

import csv

from datetime import datetime

path = "/home/haldrik/dev/python/data/dataset.csv"

file = open(path, newline='')

reader = csv.reader(file, delimiter=',')

header = next(reader) # Ignore first row.

data = []

for row in reader:

    # row = [user_id, timestamp]

    user_id = row[0]

    timestamp = datetime.strptime(row[1], '%H:%M:%S').time()

    

    data.append([user_id, timestamp])

该代码抛出此错误：

Traceback (most recent call last):

  File "/home/haldrik/dev/python/instances_web_site.py", line 15, in <module>

    date = datetime.strptime(row[1], '%H:%M:%S').time()

  File "/usr/lib/python3.8/_strptime.py", line 568, in _strptime_datetime

    tt, fraction, gmtoff_fraction = _strptime(data_string, format)

  File "/usr/lib/python3.8/_strptime.py", line 349, in _strptime

    raise ValueError("time data %r does not match format %r" %

ValueError: time data '' does not match format '%H:%M:%S'

我找不到错误在哪里。我可以看到数据格式符合指定的时间格式。

倒出 cvs 导入步骤，我可以确保它有效，请参见这段代码（未包含在上面的代码中）：

data_import = [row for row in reader]

print(data_import[0])

它输出这个：

['563','0:00:21']

Answer 1

您对 timestamp 列中的一个或多个值有疑问，其中一行看起来像440,并且会导致time data '' does not match format '%H:%M:%S'包裹date = datetime.strptime(row[1], '%H:%M:%S').time()在一个try-except块中。test.csvuser_id,timestamp563,0:00:21671,0:00:26780,0:00:28440,代码import csvfrom datetime import datetimepath = "test.csv"file = open(path, newline='')reader = csv.reader(file, delimiter=',')header = next(reader) # Ignore first row.data = []for row in reader:&nbsp; &nbsp; # row = [user_id, timestamp]&nbsp; &nbsp; user_id = row[0]&nbsp; &nbsp; try:&nbsp; &nbsp; &nbsp; &nbsp; timestamp = datetime.strptime(row[1], '%H:%M:%S').time()&nbsp; &nbsp; except ValueError as e:&nbsp; &nbsp; &nbsp; &nbsp; timestamp = row[1]#&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;continue&nbsp; # use this if you do not want the row added to data, comment it out otherwise&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; data.append([user_id, timestamp])print(data)[out]:[['563', datetime.time(0, 0, 21)], ['671', datetime.time(0, 0, 26)], ['780', datetime.time(0, 0, 28)], ['440', '']]