Category: Python Answers

Sometimes, we want to get all subsets of a set with Python.

In this article, we’ll look at how to get all subsets of a set with Python.

How to get all subsets of a set with Python?

To get all subsets of a set with Python, we can use the chain.from_iterable method with the combinations function.

For instance, we write

from itertools import chain, combinations


def powerset(iterable):
    s = list(iterable)
    return chain.from_iterable(combinations(s, r) for r in range(len(s)
                               + 1))

to call chain.from_iterable with all the combinations of set s that we get from

combinations(s, r) for r in range(len(s)
                               + 1)

We convert the iterable to a list with list before we call chain.from_iterable.

Conclusion

To get all subsets of a set with Python, we can use the chain.from_iterable method with the combinations function.

Sometimes, we want to sort a list of strings numerically with Python.

In this article, we’ll look at how to sort a list of strings numerically with Python.

How to sort a list of strings numerically with Python?

To sort a list of strings numerically with Python, we convert the strings in the list to numbers before we sort them.

For instance, we write

list1 = ["1", "10", "3", "22", "23", "4", "2", "200"]
list1 = [int(x) for x in list1]
list1.sort()

to convert all items in list1 to ints with

[int(x) for x in list1]

and assign the returned result back to list1.

Then we call sort to sort the items in place.

Conclusion

To sort a list of strings numerically with Python, we convert the strings in the list to numbers before we sort them.

Sometimes, we want to copy a string to the clipboard with Python.

In this article, we’ll look at how to copy a string to the clipboard with Python.

How to copy a string to the clipboard with Python?

To copy a string to the clipboard with Python, we can use the pyperclip library.

To install it, we run

pip install pyperclip

Then we use it by writing

import pyperclip
pyperclip.copy('hello world')

to call pyperclip.copy to copy ‘hello world’ into the clipboard.

Then we get the copied content and paste it with

pyperclip.paste()

Conclusion

To copy a string to the clipboard with Python, we can use the pyperclip library.

Sometimes, we want to convert Python Pandas DataFrame column type from string to datetime.

In this article, we’ll look at how to convert Python Pandas DataFrame column type from string to datetime.

How to convert Python Pandas DataFrame column type from string to datetime?

To convert Python Pandas DataFrame column type from string to datetime, we can use the to_datetime method.

For instance, we write

df['col'] = pd.to_datetime(df['col'])

to call to_datetime with the col data frame column and assign it back to it after converting the values to datetime.

Conclusion

To convert Python Pandas DataFrame column type from string to datetime, we can use the to_datetime method.

Sometimes, we want to save and load cookies using Python and Selenium WebDriver.

In this article, we’ll look at how to save and load cookies using Python and Selenium WebDriver.

How to save and load cookies using Python and Selenium WebDriver?

To save and load cookies using Python and Selenium WebDriver, we can save and get cookies with pickle.

For instance, we write

import pickle
import selenium.webdriver

driver = selenium.webdriver.Firefox()
driver.get("http://www.example.com")
pickle.dump(driver.get_cookies() , open("cookies.pkl","wb"))

to call pickle.dump with the cookies we get from driver.get_cookies.

And then we get the saved cookie with pickle.load by writing

import pickle
import selenium.webdriver

driver = selenium.webdriver.Firefox()
driver.get("http://www.example.com")
cookies = pickle.load(open("cookies.pkl", "rb"))
for cookie in cookies:
    driver.add_cookie(cookie)

We call pickle.load with the opened pickle file to load the cookies.

And then we call driver.add_cookie to add the cookie into the opened page.

Conclusion

To save and load cookies using Python and Selenium WebDriver, we can save and get cookies with pickle.