Category: Python Answers

Sometimes, we want to extract extension from filename in Python.

In this article, we’ll look at how to extract extension from filename in Python.

How to extract extension from filename in Python?

To extract extension from filename in Python, we can use the splitext method.

For instance, we write

import os

filename, file_extension = os.path.splitext('/path/to/somefile.ext')

to call os.path.splitext with the file path string that we to extract the file extension from.

We get the first file_extension from the 2nd item in the returned tuple.

Conclusion

To extract extension from filename in Python, we can use the splitext method.

Sometimes, we want to remove the ANSI escape sequences from a string in Python.

In this article, we’ll look at how to remove the ANSI escape sequences from a string in Python.

How to remove the ANSI escape sequences from a string in Python?

To remove the ANSI escape sequences from a string in Python, we call the regex sub method.

For instance, we write

def escape_ansi(line):
    ansi_escape = re.compile(r"(?:\x1B[@-_]|[\x80-\x9F])[0-?]*[ -/]*[@-~]")
    return ansi_escape.sub("", line)

to create the escape_ansi function.

In it, we call re.compile with a string to match all the ANSI escape characters.

And then we call ansi_escape.sub to replace the matched values with empty strings in the line string and return the string with the replacement done.

Conclusion

To remove the ANSI escape sequences from a string in Python, we call the regex sub method.

Sometimes, we want to sum the digits of a number with Python.

In this article, we’ll look at how to sum the digits of a number with Python.

How to sum the digits of a number with Python?

To sum the digits of a number with Python, we can create our own function.

For instance, we write

def sum_digits(n):
    s = 0
    while n:
        s += n % 10
        n //= 10
    return s

to create the sum_digits function that has a while loop that runs when n isn’t 0.

In it, we get the remainder of n with divided by 10 with n % 10.

Then we add the remainder to s.

Next, we divide n by 10 and round the quotient to the nearest integer.

And then we return the sum s.

Conclusion

To sum the digits of a number with Python, we can create our own function.

Sometimes, we want to create permutations between two lists of unequal length with Python.

In this article, we’ll look at how to create permutations between two lists of unequal length with Python.

How to create permutations between two lists of unequal length with Python?

To create permutations between two lists of unequal length with Python, we can use the itertools.product method.

For instance, we write

a = ["foo", "melon"]
b = [True, False]
c = list(itertools.product(a, b))

to call itertools.product with a and b to return an iterator with the tuples with the different permutations of items between a and b.

Then we convert that to a list with list.

Conclusion

To create permutations between two lists of unequal length with Python, we can use the itertools.product method.

Sometimes, we want to use Python strptime() with timezones.

In this article, we’ll look at how to use Python strptime() with timezones.

How to use Python strptime() with timezones?

To use Python strptime() with timezones, we can use dateutil.

To install it, we run

pip install python-dateutil

Then we use it by writing

from dateutil import parser
d = parser.parse("Tue Jun 22 07:46:22 EST 2022")

to call parser.parse with the datetime string with the time zone.

Conclusion

To use Python strptime() with timezones, we can use dateutil.