Author: John Au-Yeung

Sometimes, we want to convert a datetime object to milliseconds since epoch (Unix time) in Python.

In this article, we’ll look at how to convert a datetime object to milliseconds since epoch (Unix time) in Python.

How to convert a datetime object to milliseconds since epoch (Unix time) in Python?

To convert a datetime object to milliseconds since epoch (Unix time) in Python, we can subtract the datetime from the epoch datetime.

And then we call total_seconds on the difference and multiply that by 1000.

For instance, we write:

import datetime

epoch = datetime.datetime.utcfromtimestamp(0)


def unix_time_millis(dt):
    return (dt - epoch).total_seconds() * 1000.0


dt = datetime.datetime(2020, 1, 1)
print(unix_time_millis(dt))

We use datetime.datetime.utcfromtimestamp(0) to create the Unix epoch datetime.

Then we define the unix_time_millis function that subtracts dt from epoch and call total_seconds on the difference.

And then we multiply that by 1000 to get the difference in milliseconds,

Next, we call unix_time_millis with dt to return the difference of dt since the Unix epoch in milliseconds.

Therefore, print should print 1577836800000.0.

Conclusion

To convert a datetime object to milliseconds since epoch (Unix time) in Python, we can subtract the datetime from the epoch datetime.

And then we call total_seconds on the difference and multiply that by 1000.

Sometimes, we want to find the time difference between two datetime objects in Python.

In this article, we’ll look at how to find the time difference between two datetime objects in Python.

How to find the time difference between two datetime objects in Python?

To find the time difference between two datetime objects in Python, we can subtract 2 datetime objects directly.

For instance, we write;

import datetime

first_time = datetime.datetime(2021, 1, 1)
later_time = datetime.datetime(2021, 1, 5)
diff = later_time - first_time
print(diff)

We create a datetime objects with the datetime.datetime method.

Then we subtract later_time from first_time and assign that to diff.

Then from the print output, we see that diff is 4 days, 0:00:00.

Conclusion

To find the time difference between two datetime objects in Python, we can subtract 2 datetime objects directly.

Sometimes, we want to delete a list element by value with Python.

In this article, we’ll look at how to delete a list element by value with Python.

How to delete a list element by value with Python?

To delete a list element by value with Python, we can use the remove method.

For instance, we write:

a = ['a', 'b', 'c', 'd']
a.remove('b')
print(a)

We call a.remove to remove 'b' from a.

Therefore, a is now ['a', 'c', 'd'].

Conclusion

To delete a list element by value with Python, we can use the remove method.

Sometimes, we want to convert number words to integers with Python.

In this article, we’ll look at how to convert number words to integers with Python.

How to convert number words to integers with Python?

To convert number words to integers with Python, we can use the word2number module.

To install it, we run:

pip install word2number

Then we write:

from word2number import w2n

n = w2n.word_to_num("ten million three thousand nine hundred and twenty four")
print(n)

We call w2n.word_to_num with the English number string that we want to convert into a number.

Then we assign the returned number to n.

Therefore, n is 10003924.

Conclusion

To convert number words to integers with Python, we can use the word2number module.

Sometimes, we want to convert a binary number string to an int with Python.

In this article, we’ll look at how to convert a binary number string to an int with Python.

How to convert a binary number string to int with Python?

To convert a binary number string to an int with Python, we can call the int function with the number string to convert and base 2.

For instance, we write:

n = int('11111111', 2)
print(n)

We call int with '11111111' and 2 to convert '11111111' to a decimal int and assign that to n.

Therefore, n is 255.

Conclusion

To convert a binary number string to an int with Python, we can call the int function with the number string to convert and base 2.