Convert string to only time python

I have the following Pandas dataframe in Python 2.7.

import pandas as pd
trial_num = [1,2,3,4,5]
sail_rem_time = ['11:33:11','16:29:05','09:37:56','21:43:31','17:42:06']
dfc = pd.DataFrame[zip[*[trial_num,sail_rem_time]],columns=['Temp_Reading','Time_of_Sail']]
print dfc

The dataframe looks like this:

  Temp_Reading Time_of_Sail
             1     11:33:11
             2     16:29:05
             3     09:37:56
             4     21:43:31
             5     17:42:06

This dataframe comes from a *.csv file. I use Pandas to read in the *.csv file as a Pandas dataframe. When I use print dfc.dtypes, it shows me that the column Time_of_Sail has a datatype object. I would like to convert this column to datetime datatype BUT I only want the time part - I don't want the year, month, date.

I can try this:

dfc['Time_of_Sail'] = pd.to_datetime[dfc['Time_of_Sail']]
dfc['Time_of_Sail'] = [time.time[] for time in dfc['Time_of_Sail']]

but the problem is that the when I run print dfc.dtypes it still shows that the column Time_of_Sail is object.

Is there a way to convert this column into a datetime format that only has the time?

Additional Information:

To create the above dataframe and output, this also works:

import pandas as pd
trial_num = [1,2,3,4,5]
sail_rem_time = ['11:33:11','16:29:05','09:37:56','21:43:31','17:42:06']
data = [
    [trial_num[0],sail_rem_time[0]],
    [trial_num[1],sail_rem_time[1]],[trial_num[2],sail_rem_time[2]],
    [trial_num[3],sail_rem_time[3]]
    ]
dfc = pd.DataFrame[data,columns=['Temp_Reading','Time_of_Sail']]
dfc['Time_of_Sail'] = pd.to_datetime[dfc['Time_of_Sail']]
dfc['Time_of_Sail'] = [time.time[] for time in dfc['Time_of_Sail']]
print dfc
print dfc.dtypes

We can convert a string to datetime using strptime[] function. This function is available in datetime and time modules to parse a string to datetime and time objects respectively.

Python strptime[]

Python strptime[] is a class method in datetime class. Its syntax is:

datetime.strptime[date_string, format]

Both the arguments are mandatory and should be string. This function is exactly opposite of strftime[] function, which converts datetime object to a string. We have the similar function available in time module too, where its syntax is:

time.strptime[time_string[, format]]

Here the function returns struct_time object. If format string is not provided, it defaults to “%a %b %d %H:%M:%S %Y” which matches the formatting returned by ctime[] function. If the input string cannot be parsed according to the provided format, then ValueError is raised. The exception message provides clear details about the issue in parsing.

Python strptime[] format directives

Following table contains most of the commonly used format directives.

Python strptime[] examples

Let’s look into some specific examples of strptime[] function to convert string to datetime and time objects.

String to datetime

from datetime import datetime

datetime_str = '09/19/18 13:55:26'

datetime_object = datetime.strptime[datetime_str, '%m/%d/%y %H:%M:%S']

print[type[datetime_object]]
print[datetime_object]  # printed in default format

Output:

2018-09-19 13:55:26

String to date object

We can use date[] function alongwith strptime[] function to convert string to date object.

date_str = '09-19-2018'

date_object = datetime.strptime[date_str, '%m-%d-%Y'].date[]
print[type[date_object]]
print[date_object]  # printed in default formatting

Output:

2018-09-19

String to time object

We can use time[] function alongwith strptime[] function to convert string to time object.

time_str = '13::55::26'
time_object = datetime.strptime[time_str, '%H::%M::%S'].time[]
print[type[time_object]]
print[time_object]

Output:

13:55:26

Python time strptime[] example

Let’s see some examples of using time module strptime[] function.

import time

time_obj = time.strptime[time_str, '%H::%M::%S']
print[type[time_obj]]
print[time_obj]

# default formatting - "%a %b %d %H:%M:%S %Y"
print[time.strptime['Wed Sep 19 14:55:02 2018']]

Output:

time.struct_time[tm_year=1900, tm_mon=1, tm_mday=1, tm_hour=13, tm_min=55, tm_sec=26, tm_wday=0, tm_yday=1, tm_isdst=-1]
time.struct_time[tm_year=2018, tm_mon=9, tm_mday=19, tm_hour=14, tm_min=55, tm_sec=2, tm_wday=2, tm_yday=262, tm_isdst=-1]

Python strptime[] ValueError Example

We can use try-except block to catch parsing exception and perform corrective actions.

datetime_str = '09/19/18 13:55:26'

try:
    datetime_object = datetime.strptime[datetime_str, '%m/%d/%y']
except ValueError as ve:
    print['ValueError Raised:', ve]

time_str = '99::55::26'

try:
    time_object = time.strptime[time_str, '%H::%M::%S']
except ValueError as e:
    print['ValueError:', e]

Output:

ValueError Raised: unconverted data remains:  13:55:26
ValueError: time data '99::55::26' does not match format '%H::%M::%S'

Notice that the ValueError message clearly explains the root cause of the parsing exception.

Python Convert String to Datetime with locale

Let’s look at an example where a locale-specific string will be converted to datetime object. We will use locale module to set the locale to be used by python.

import locale

locale.setlocale[locale.LC_ALL, 'de_DE']
date_str_de_DE = '10-Dezember-2018 Montag'  # de_DE locale
datetime_object = datetime.strptime[date_str_de_DE, '%d-%B-%Y %A']
print[datetime_object]

Output: 2018-12-10 00:00:00

You can checkout complete python script and more Python examples from our GitHub Repository.

References: datetime strptime[], time strptime[]

How do you convert a string to just time in Python?

How do you convert string to UTC time in Python?

How do you convert a date without time in Python?

How do I convert a string to a date?