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Converting string to datetime [hh:mm:ss]

I have two columns Date_x and Date_y. I would like to compare them (i.e Date_x + 1 hour < Date_y)
Format of the strings looks as follows "2020-01-29 11:31:32.754292 UTC"
I have tried converting it using datetime:
from datetime import datetime as dt
df["Date_x"] = [dt.strptime(x, '%Y-%m-%d %H:%M:%S.%f') for x in df['Date_x']]
However, it throws an error regarding the UTC part. I tried removing it with no avail.
Last traceback:
time data '2020-01-29 18:30:28' does not match format '%Y-%m-%d %H:%M:%S.%f'
How would you go about converting the string to hh:mm:ss only?

You could use an if statement:
df["Date_x"] = [dt.strptime(x, '%Y-%m-%d %H:%M:%S.%f') if '.' in x else dt.strptime(x, '%Y-%m-%d %H:%M:%S') for x in df['Date_x']]
But why not just pd.to_datetime:
df["Date_x"] = pd.to_datetime(df["Date_x"], infer_datetime_format=True)

Unable to get time difference between to pandas dataframe columns

I have a pandas dataframe that contains a couple of columns. Two of which are start_time and end_time. In those columns the values look like - 2020-01-04 01:38:33 +0000 UTC
I am not able to create a datetime object from these strings because I am not able to get the format right -
df['start_time'] = pd.to_datetime(df['start_time'], format="yyyy-MM-dd HH:mm:ss +0000 UTC")
I also tried using yyyy-MM-dd HH:mm:ss %z UTC as a format
This gives the error -
ValueError: time data '2020-01-04 01:38:33 +0000 UTC' does not match format 'yyyy-MM-dd HH:mm:ss +0000 UTC' (match)

You just need to use the proper timestamp format that to_datetime will recognize
df['start_time'] = pd.to_datetime(df['start_time'], format="%Y-%m-%d %H:%M:%S +0000 UTC")

There are some notes below about this problem:
1. About your error
This gives the error -
You have parsed a wrong datetime format that will cause the error. For correct format check this one https://strftime.org/. Correct format for this problem would be: "%Y-%m-%d %H:%M:%S %z UTC"
2. Pandas limitation with timezone
Parsing UTC timezone as %z doesn't working on pd.Series (it only works on index value). So if you use this, it will not work:
df['startTime'] = pd.to_datetime(df.startTime, format="%Y-%m-%d %H:%M:%S %z UTC", utc=True)
Solution for this is using python built-in library for inferring the datetime data:
from datetime import datetime
f = lambda x: datetime.strptime(x, "%Y-%m-%d %H:%M:%S %z UTC")
df['startTime'] = pd.to_datetime(df.startTime.apply(f), utc=True)
#fmarm answer only help you dealing with date and hour data, not UTC timezone.

Finding the right format for pd.to_datetime

I'm trying to convert strings in my dataset('2016-01-01 00:00:00') to time stamps using pd.to_datetime.
Im trying:
pd.to_datetime(train["timestamp"],format='%Y/%m/%d %I:%M:%S')
but I get
time data '2016-01-01 00:00:00' does not match format '%Y/%m/%d %I:%M:%S' (match)
How can I fix this?

If you want it to be in the specific format that you mentioned, that is %Y/%m/%d %I:%M:%S, then do it like this.
First convert your string to datetime format using to_datetime:
df['timestamp'] = pd.to_datetime(df['timestamp'])
Now that your column is in datetime format, convert to the following format using strftime:
df['timestamp'] = df['timestamp'].dt.strftime('%Y/%m/%d %I:%M:%S')
Output:
timestamp
0 2016/01/01 12:00:00
1 2016/01/01 12:00:00
As others pointed out, use %H instead of %I for 24 hour format, like this:
df['timestamp'] = df['timestamp'].dt.strftime('%Y/%m/%d %H:%M:%S')

That's because your format in your df is different. Try the following using -, also use %H for 24-hour clock:
pd.to_datetime(train["timestamp"],format='%Y-%m-%d %H:%M:%S')

2 issues here:
Use - instead of /
%I is for Hour 00-12, use %H for Hour 00-23
pd.to_datetime(train["timestamp"],format='%Y-%m-%d %H:%M:%S')

Cannot find the correct way to change string time to datetime

I have a df column with the following days example 2018-07-25 19:23:17.000000
and i cannot find the correct way to convert this string into a datetime value
I've been trying with the following code
dfa['time_event_utc'] = pd.to_datetime(df['time_event_utc'],format='%d%b%Y:%H:%M:%S +000000',utc=True)

your format is '%Y-%m-%d %H:%M:%S.%f'
mydt = '2018-07-25 19:23:17.000000'
datetime.datetime.strptime(mydt , '%Y-%m-%d %H:%M:%S.%f')

Converting string to date that contains 00:00:00

To convert a string date to date format dropping the '00:00:00' I use :
import datetime
strDate = '2017-04-17 00:00:00'
datetime.datetime.strptime(strDate, '%Y/%m/%d %H:%M:%S').strftime('%Y-%m-%d')
Returns :
ValueError: time data '2017-04-17 00:00:00' does not match format '%Y/%m/%d %H:%M:%S'
Is %H:%M:%S not correct format ?

This is the correct way:
datetime.datetime.strptime(strDate, '%Y-%m-%d %H:%M:%S').strftime('%Y-%m-%d')
Notice the - instead of / in strptime. The date is converted to: 2017-04-17.
If you would like to have it displayed a different way, have a look here.