Category: Python

Sometimes, we want to extract an attribute value with Python BeautifulSoup.

In this article, we’ll look at how to extract an attribute value with Python BeautifulSoup.

How to extract an attribute value with Python BeautifulSoup?

To extract an attribute value with Python BeautifulSoup, we can use the find_all method.

For instance, we write:

import requests
from bs4 import BeautifulSoup

r = requests.get("https://www.crummy.com/software/BeautifulSoup/bs4/doc/")
soup = BeautifulSoup(r.text, 'html.parser')

res = soup.find_all(attrs={"class": 'document'})

print(res)

We make a GET request to get the content of https://www.crummy.com/software/BeautifulSoup/bs4/doc/.

Then we get the HTML text with r.text and use that as the argument of the BeautifulSoup constructor.

Then we find all the elements with the class attribute set to document with:

a = soup.find_all(attrs={"class": 'document'})

Conclusion

To extract an attribute value with Python BeautifulSoup, we can use the find_all method.

Sometimes, we want to test if a string contains one of the substrings in a list in Python Pandas.

In this article, we’ll look at how to test if a string contains one of the substrings in a list in Python Pandas.

How to test if a string contains one of the substrings in a list in Python Pandas?

To test if a string contains one of the substrings in a list in Python Pandas, we can use the str.contains method with a regex pattern to find all the matches.

For instance, we write:

import pandas as pd

s = pd.Series(['cat', 'hat', 'dog', 'fog', 'pet'])
df = pd.DataFrame([('cat', 1000.0), ('hat', 2000000.0), ('dog', 1000.0),
                   ('fog', 330000.0), ('pet', 330000.0)],
                  columns=['col1', 'col2'])
r = df[s.str.contains('cat|pet')]
print(r)

We create a series with the pd.Series constructor.

Then we create a DataFrame with the pd.DataFrame constructor.

Next, we call s.str.contains with the words we’re looking for separated by a |.

And then we assign the matches to r.

Therefore, r is:

  col1      col2
0  cat    1000.0
4  pet  330000.0

Conclusion

To test if a string contains one of the substrings in a list in Python Pandas, we can use the str.contains method with a regex pattern to find all the matches.

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 package.

To install it, we run:

pip install pyperclip

Then we use it by writing:

import pyperclip

pyperclip.copy("your string")

We can paste the content of the clipboard with:

clipboard_content = pyperclip.paste()

Conclusion

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

Sometimes, we want to concatenate text files in Python.

In this article, we’ll look at how to concatenate text files in Python.

How to concatenate text files in Python?

To concatenate text files in Python, we can use the with statement and the open function.

For instance, we write:

filenames = ['file1.txt', 'file2.txt']
with open('file.txt', 'w') as outfile:
    for fname in filenames:
        with open(fname) as infile:
            for line in infile:
                outfile.write(line)

We have the filenames list that has the paths of the files we want to join together.

Then we call open with the file we want to write the combined file contents to.

In the with block, we have a for loop to loop through the filenames and open each fname entry with open.

Then we loop through each line of each open file and call outfile.write to write each line in the input files.

Conclusion

To concatenate text files in Python, we can use the with statement and the open function.

Sometimes, we want to iterate over files in a given directory with Python.

In this article, we’ll look at how to iterate over files in a given directory with Python.

How to iterate over files in a given directory with Python?

To iterate over files in a given directory with Python, we can use the os.listdir method.

For instance, we write:

import os

directory = os.fsencode('./')

for file in os.listdir(directory):    
    filename = os.fsdecode(file)
    if filename.endswith(".py"):
        print(os.path.join(directory.decode('utf-8'), filename))

We call os.fsencode with the directory string to create the directory byte string.

Then we call os.listdir with directory to loop through the entries in the directory.

Then we call os.fsdecode with file to get the filename of the file.

And then we call os.path.join with path segment strings to print the full path of each file.

Conclusion

To iterate over files in a given directory with Python, we can use the os.listdir method.