Python time difference in milliseconds

Python Time Difference in Milliseconds: 5 Methods to Calculate with Code Examples

Learn how to calculate time difference in milliseconds between two datetime objects in Python. Explore 5 methods with code examples and tips for using timedelta, time_ns(), Pandas, and getTime().

• Understanding datetime Objects and Timedelta Class
• 1. Using Timedelta Class
• Calculate Time Difference in Milliseconds Between Two
• 2. Using time_ns() Function
• 3. Using a Hack
• 4. Using Pandas
• 5. Using getTime() Method
• Other Python code examples for getting time difference in milliseconds
• Conclusion
• How do you calculate time difference in milliseconds in Python?
• How to extract milliseconds from timestamp in Python?
• Which function returns the time difference in milliseconds?
• How do I get the time difference between two Datetimes in Python?

If you’re working with time-series data in Python, you’re likely to come across a need to calculate the time difference in milliseconds between two datetime objects. Python provides several methods to accomplish this task, each with its own advantages and disadvantages. In this blog post, we’ll explore five different methods to calculate the time difference in milliseconds between two datetime objects in Python.

Understanding datetime Objects and Timedelta Class

Before we dive into the methods, let’s take a moment to understand the datetime objects and timedelta class in python. A datetime object represents a date and time, and it has several attributes such as year, month, day, hour, minute, second, and microsecond. The timedelta class, on the other hand, represents the difference between two datetime objects in days, seconds, and microseconds.

1. Using Timedelta Class

The timedelta class provides a simple and straightforward way to calculate the time difference in milliseconds between two datetime objects. To calculate the time difference in milliseconds, we can use the total_seconds() method along with multiplication by 1000, as shown in the following code snippet:

from datetime import datetime, timedeltastart_time = datetime.now() # Do some work here end_time = datetime.now()time_diff = end_time - start_time milliseconds_diff = time_diff.total_seconds() * 1000 

Here, we are subtracting the start_time from the end_time to get the time difference, and then multiplying it by 1000 to convert it into milliseconds.

Calculate Time Difference in Milliseconds Between Two

2. Using time_ns() Function

Python 3.7 introduced the time_ns() function, which returns the current time in nanoseconds. We can use this function to get the current time in milliseconds, as shown in the following code snippet:

import timestart_time = time.time_ns() # Do some work here end_time = time.time_ns()time_diff = end_time - start_time milliseconds_diff = time_diff / 1000000 

Here, we are subtracting the start_time from the end_time to get the time difference in nanoseconds, and then dividing it by 1000000 to convert it into milliseconds.

3. Using a Hack

This method involves adding the same date to both datetime objects and subtracting them to get the time difference in microseconds. We can then divide the result by 1000 to convert it into milliseconds, as shown in the following code snippet:

from datetime import datetimestart_time = datetime.now() # Do some work here end_time = datetime.now()time_diff = end_time.replace(year=1970, month=1, day=1, tzinfo=None) - start_time.replace(year=1970, month=1, day=1, tzinfo=None) milliseconds_diff = time_diff.microseconds / 1000 

Here, we are replacing the year, month, and day of both datetime objects with the same values to get a valid datetime object. We then subtract the start_time from the end_time to get the time difference in microseconds, and then divide it by 1000 to convert it into milliseconds.

4. Using Pandas

If you’re working with time-series data, you’re likely to be using the Pandas library. Pandas provides powerful data analysis tools for working with time-series data, including the ability to calculate the time difference in milliseconds between two datetime objects. We can use the pd.to_datetime() method to convert datetime strings to datetime objects, and the pd.Timedelta() method to calculate the time difference in milliseconds, as shown in the following code snippet:

import pandas as pdstart_time = pd.to_datetime('2021-01-01 00:00:00') # Do some work here end_time = pd.to_datetime('2021-01-01 00:00:01')time_diff = end_time - start_time milliseconds_diff = time_diff / pd.Timedelta(milliseconds=1) 

Here, we are converting the datetime strings to datetime objects using the pd.to_datetime() method. We then subtract the start_time from the end_time to get the time difference, and then divide it by the Timedelta object with a value of 1 millisecond to convert it into milliseconds.

5. Using getTime() Method

This method is commonly used in JavaScript, but can also be used in Python. The getTime() method returns the time difference in milliseconds since the epoch, which is January 1, 1970. We can use this method along with the datetime.fromtimestamp() method to calculate the time difference in milliseconds between two datetime objects, as shown in the following code snippet:

import time from datetime import datetimestart_time = int(time.time() * 1000) # Do some work here end_time = int(time.time() * 1000)time_diff = datetime.fromtimestamp(end_time / 1000) - datetime.fromtimestamp(start_time / 1000) milliseconds_diff = time_diff.total_seconds() * 1000 

Here, we are using the time.time() method to get the current time in seconds since the epoch, and then multiplying it by 1000 to convert it into milliseconds. We then subtract the start_time from the end_time to get the time difference, and then convert it into a datetime object using the datetime.fromtimestamp() method. Finally, we use the total_seconds() method to get the time difference in seconds, and then multiply it by 1000 to convert it into milliseconds.

Other Python code examples for getting time difference in milliseconds

In Python as proof, python print time difference code sample

>>> import datetime >>> a = datetime.datetime.now() >>> b = datetime.datetime.now() >>> c = b - a>>> c datetime.timedelta(0, 4, 316543) >>> c.days 0 >>> c.seconds 4 >>> c.microseconds 316543

>>> import datetime >>> a = datetime.datetime.now() >>> b = datetime.datetime.now() >>> delta = b - a >>> print delta 0:00:05.077263 >>> int(delta.total_seconds() * 1000) # milliseconds 5077 

Conclusion

Python provides various methods to calculate the time difference in milliseconds between two datetime objects. Depending on your use case, one method may be more suitable than the others. Understanding the timedelta class, time_ns() function, and Pandas library are essential for calculating time differences in Python. With the code examples and explanations provided in this blog post, you should be able to choose the method that best suits your needs.

Источник

Calculate Time Difference in Milliseconds Between Two datetimes in Python (Example)

In this Python tutorial, you’ll learn how to return the time difference between two datetimes in milliseconds.

The post is structured as follows:

Example Data

For the examples of this tutorial, we’ll also have to import the datetime module:

import datetime # Import datetime module

Now, we create two example datetimes, consider the two code boxes below:

my_date_1 = datetime.datetime(2022, 5, 24, 11, 20, 12, 987123) # 1st example datetime object print(my_date_1) # 2022-05-24 11:20:12.987123

my_date_2 = datetime.datetime(2022, 6, 16, 13, 30, 27, 189553) # 2nd example datetime object print(my_date_2) # 2022-06-16 13:30:27.189553

Let’s compute these two datetime objects and find out the time difference…

Example: Show the Time Difference in Milliseconds

To get the time difference of two datetime objects, we simply subtract them from each other:

my_diff_default = my_date_2 - my_date_1 # Get default time difference print(my_diff_default) # 23 days, 2:10:14.202430

As you can see on the output above, the default timedelta is not in milliseconds.

To receive the time difference in milliseconds, we have to do a little workaround by applying the total_seconds function, which transforms the time difference into seconds, followed by a multiplication with factor 1000:

my_diff_milli_sec = my_diff_default.total_seconds() * 1000 # Return difference in milliseconds print(my_diff_milli_sec) # 1995014202.43

That’s it, the time difference between our two datetimes is: 1995014202.43 milliseconds.

Video & Further Resources

I have recently released a video on the Statistics Globe YouTube channel, which shows the Python programming syntax of this article. Please find the video below.

Please accept YouTube cookies to play this video. By accepting you will be accessing content from YouTube, a service provided by an external third party.

If you accept this notice, your choice will be saved and the page will refresh.

Accept YouTube Content

Furthermore, you might want to have a look at the other tutorials on this website.

Summary: In this Python tutorial, you have learned how to print the difference between two datetimes in milliseconds. If you have any additional questions, please let me know in the comments. Furthermore, don’t forget to subscribe to my email newsletter for updates on the newest tutorials.

This page was created in collaboration with Matthias Bäuerlen. Have a look at Matthias’ author page to get more information about his professional background, a list of all his tutorials, as well as an overview on his other tasks on Statistics Globe.

Источник