将字符串转换为datetime到epoch

Question

I am using Python to query a MySQL table and getting one datetime in string format, which is stored in row[3] . I need to convert this string timestamp to epoch seconds.

import MySQLdb
import os
import datetime
try:
    db = MySQLdb.connect("localhost","root","","test" )
except MySQLdb.Error, e:
     print "Error %d: %s" % (e.args[0], e.args[1])
     sys.exit (1)

cursor = db.cursor()
cursor.execute ("SELECT * from main_tbl WHERE login_user_name='kumar'")
data = cursor.fetchall()

for row in data :
    print row[3]                                   ###printing 2014-09-26 12:24:23
    date = datetime.datetime.strptime(row[3], "%Y-%m-%d %H:%M:%S")
    print date

On execution it throws this error:

2014-09-26 12:24:23
Traceback (most recent call last):
  File "test1.py", line 22, in <module>
    date = datetime.datetime.strptime(row[3], "%Y-%m-%d %H:%M:%S")
TypeError: must be string, not datetime.datetime

What am I doing wrong?

I have also tried the following:

epoch_start = time.mktime(time.strptime(row[3], "%Y-%m-%d %H:%M:%S"));

But I get this error:

Traceback (most recent call last):
  File "test1.py", line 29, in <module>
    epoch_start = time.mktime(time.strptime(row[3], "%Y-%m-%d %H:%M:%S"));
  File "C:\Python27\lib\_strptime.py", line 467, in _strptime_time
    return _strptime(data_string, format)[0]
  File "C:\Python27\lib\_strptime.py", line 322, in _strptime
    found = format_regex.match(data_string)
TypeError: expected string or buffer

Answer 1

The value in row[3] is already in the datetime.datetime format as it is being clearly pointed out by the traceback. So there is no need for creating the variable date . You can use the row[3] directly as a datetime.datetime object.

Just try printing:

print type(row[3])

That should give the type as datetime.datetime

Answer 2

row[3] is already in datetime.datetime format.

From your question its sounds like you want convert to EPOCH so do something like:

import time
epochTime = time.mktime(row[3].timetuple())
print epochTime

Then check if the converted epoch is correct or not:

print time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(epochTime))
print row[3]

Verify last two statements have the same output.