ValueError：时间数据与格式'％Y-％m-％d％H：％M：％S.％f'不匹配

我面临一个小问题。我正在存储一些日期时间数据，该数据是

# "datetime","numb","temperature"

"1998-04-18 16:48:36.76",0,38
"1998-04-18 16:48:36.8",1,42
"1998-04-18 16:48:36.88",2,23
"1998-04-18 16:48:36.92",3,24
"1998-04-18 16:48:36",4,42
"1998-04-18 16:48:37",5,33
"1998-04-18 16:48:37.08",6,25

日期时间列显然是字符串，所以当我尝试将其转换时，出现此错误

ValueError: time data '1998-04-18 16:48:36' does not match format '%Y-%m-%d %H:%M:
%S.%f'

我的代码是

import time
import datetime
import calendar

for k, line in enumerate(lines):
                if k > (int(header_line)):
                    data_pre = line.strip().split(',')
                    stDate = data_pre[0].replace("\"", "")
                    print stDate  # got 1998-04-18 16:48:36.76


                    dat_time = datetime.datetime.strptime(stDate,
                                                       '%Y-%m-%d %H:%M:%S.%f')
                    mic_sec = dat_time.microsecond
                    timcon = calendar.timegm(dat_time.timetuple())*1000000 + mic_sec
                    strDate = "\"" + strDate + "\""
                    print stDate # got "1998-04-18 16:48:36.76"

因为我的某些datetime列缺少。％f值，所以出现了此错误。我的文档可能包含数千个这样的日期时间值，因此我想出了在所有此类日期时间后附加.0的解决方案。因此，如果日期时间字符串是

"1998-04-18 16:48:36"

我的代码应附加.0以符合格式标准。例如

"1998-04-18 16:48:36.0"

我尝试将.0附加到stDate，但出现此错误

AttributeError: 'str' object has no attribute 'append'

如果有人给我一个线索，如何处理这样的问题。任何帮助将不胜感激。

更新：我浏览了您的代码，发现了一些错误类型。此外，您似乎没有添加串联。

我都整理了。

错误类型：

你写了：

for k, line in enumerate(lines):
                if k > (int(header_line)):
                    data_pre = line.strip().split(',')
                    stDate = data_pre[0].replace("\"", "")
                    print stDate  # got 1998-04-18 16:48:36.76


                    dat_time = datetime.datetime.strptime(stDate,
                                                   '%Y-%m-%d %H:%M:%S.%f')
                    mic_sec = dat_time.microsecond
                    timcon = calendar.timegm(dat_time.timetuple())*1000000 + mic_sec

                    strDate = "\"" + strDate + "\""
                    # ^ This line is wrong
                    # It should say: 
                    # strDate = "\"" + stDate + "\""

                    print stDate # got "1998-04-18 16:48:36.76"
                    # ^ This line is wrong
                    # It should say:
                    # print strDate

实施上述更改后，我们现在可以在代码示例中添加“ +“ .0”“

（尝试先运行此程序，在继续之前，确保您了解它在做什么）：

import time
import datetime
import calendar

A = "1998-04-18 16:48:36.76,0,38"
B = "1998-04-18 16:48:37,5,33"

# Run the Code for B

data_pre = B.strip().split(',')
print data_pre

stDate = data_pre[0].replace("\"", "")
print "stDate before: ", stDate  

### Addition of Addition of .0
# Here, we try to convert to datetime format using the format
# '%Y-%m-%d %H:%M:%S.%f'
try:
    dat_time = datetime.datetime.strptime(stDate,
                               '%Y-%m-%d %H:%M:%S.%f')

# If that doesn't work, we add ".4" to the end of stDate
# (You can change this to ".0")
# We then retry to convert stDate into datetime format                                   
except:
    stDate = stDate + ".4"
    dat_time = datetime.datetime.strptime(stDate,
                               '%Y-%m-%d %H:%M:%S.%f')
    print "stDate after: ", stDate

###                                
print "dat_time: ", dat_time

mic_sec = dat_time.microsecond
print "mic_sec: ", mic_sec

timcon = calendar.timegm(dat_time.timetuple())*1000000 + mic_sec
print "timecon: ", timcon

strDate = "\"" + stDate + "\""
print "strDate: ", strDate 

因此，举个例子：

A = "1998-04-18 16:48:36.76,0,38"
B = "1998-04-18 16:48:37,5,33"
# Note the difference  ^^

# Output for B:
['1998-04-18 16:48:37', '5', '33']
stDate before:  1998-04-18 16:48:37
stDate after:  1998-04-18 16:48:37.4
dat_time:  1998-04-18 16:48:37.400000
mic_sec:  400000
timecon:  892918117400000
strDate:  "1998-04-18 16:48:37.4"

# Output for A:
['1998-04-18 16:48:36.76', '0', '38']
stDate before:  1998-04-18 16:48:36.76
dat_time:  1998-04-18 16:48:36.760000
mic_sec:  760000
timecon:  892918116760000
strDate:  "1998-04-18 16:48:36.76"

将所有内容集成到您的主循环中。这是您总体上想要的：

for k, line in enumerate(lines):
                if k > (int(header_line)):
                    data_pre = line.strip().split(',')
                    stDate = data_pre[0].replace("\"", "")
                    print stDate  

                    try:
                        dat_time = datetime.datetime.strptime(stDate,
                               '%Y-%m-%d %H:%M:%S.%f')                                  
                    except:
                        stDate = stDate + ".4"
                        dat_time = datetime.datetime.strptime(stDate,
                               '%Y-%m-%d %H:%M:%S.%f')

                    mic_sec = dat_time.microsecond
                    timcon = calendar.timegm(dat_time.timetuple())*1000000 + mic_sec

                    strDate = "\"" + stDate + "\""
                    # ^ Changed this line
                    print strDate 
                    # ^ Changed this line

原始答案：

您不能追加到字符串。

一种选择是使用 A + B

A = "1998-04-18 16:48:36"
B = ".0"
C = A + B
C = "1998-04-18 16:48:36.0"

您也可以使用str.join：

D = "".join([A,B])
D = '1998-04-18 16:48:36.0'

有关更多信息，请参见以下问题的答案：在Python中连接字符串的首选方法是什么？