使用csv模块和datetime模块解析时间戳

debugcn 发表于 Dev

奥黛尔·奥古斯托·特鲁希略·奥罗斯科

我datetime在Python中遇到了一些问题。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])

该代码将引发以下错误：

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。

倾倒cvs导入步骤，我可以确保它可以正常工作，请参见以下代码片段（上述代码中未包含）：

data_import = [row for row in reader]
print(data_import[0])

它输出以下内容：

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

特伦顿·麦金尼

您在timestamp列中的一个或多个值存在问题，其中行看起来像440,并且将导致time data '' does not match format '%H:%M:%S'
包装date = datetime.strptime(row[1], '%H:%M:%S').time()成try-except块。

`test.csv`

user_id,timestamp
563,0:00:21
671,0:00:26
780,0:00:28
440,

码

import csv
from datetime import datetime

path = "test.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]
    try:
        timestamp = datetime.strptime(row[1], '%H:%M:%S').time()
    except ValueError as e:
        timestamp = row[1]
#         continue  # use this if you do not want the row added to data, comment it out otherwise
    
    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', '']]