Category: Python Answers

Sometimes, we want to sort a list of objects based on an attribute of the objects with Python.

In this article, we’ll look at how to sort a list of objects based on an attribute of the objects with Python.

How to sort a list of objects based on an attribute of the objects with Python?

To sort a list of objects based on an attribute of the objects with Python, we call the sorted function.

For instance, we write

new_list = sorted(ut, key=lambda x: x.count, reverse=True)

to call sorted with a few arguments.

We call it with the ut list that we want to sort, a function that returns the value of each entry we want to sort by, and the reverse argument set to True to sort in descending order.

And then we assign the sorted list that’s returned to new_list.

Conclusion

To sort a list of objects based on an attribute of the objects with Python, we call the sorted function.

Sometimes, we want to modify list entries during for loop with Python.

In this article, we’ll look at how to modify list entries during for loop with Python.

How to modify list entries during for loop with Python?

To modify list entries during for loop with Python, we can use list comprehension.

For instance, we write

a = [1, 3, 5]
b = a
a[:] = [x + 2 for x in a]
print(b)

to write [x + 2 for x in a] to add 2 to each entry in a.

And then we assign the entries back to b since the slice assignment and avoids changing the entries in a

Conclusion

To modify list entries during for loop with Python, we can use list comprehension.

Sometimes, we want to get all combinations of a list of lists with Python.

In this article, we’ll look at how to get all combinations of a list of lists with Python.

How to get all combinations of a list of lists with Python?

to get all combinations of a list of lists with Python, we can use the itertools.product method.

For instance, we write

import itertools
a = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]
p = list(itertools.product(*a))

to call itertools.product with the lists in a as arguments.

This will return an iterable with the cartesian product of the lists.

And then we call list to convert the iterable to a list.

Conclusion

to get all combinations of a list of lists with Python, we can use the itertools.product method.

Sometimes, we want to search and replace text in a file with Python.

In this article, we’ll look at how to search and replace text in a file with Python.

How to search and replace text in a file with Python?

To search and replace text in a file with Python, we can use the string replace method.

For instance, we write

with open('file.txt', 'r') as file :
  file_data = file.read()

file_data = file_data.replace('ram', 'abcd')

with open('file.txt', 'w') as file:
  file.write(file_data)

to open the file.txt file with open.

Then we call file_data.replace with the text we want to replace and the text replacement strings.

Then we call open to open the file again with 'w' to get write permission to the file.

And then we call file.write with file_data to overwrite the existing contents.

Conclusion

To search and replace text in a file with Python, we can use the string replace method.

Sometimes, we want to use a decimal range() step value with Python.

In this article, we’ll look at how to use a decimal range() step value with Python.

How to use a decimal range() step value with Python?

To use a decimal range() step value with Python, we can use NumPy’s linspace method.

For instance, we write

np.linspace(0, 1, 11)

to create the [ 0. , 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1. ] NumPy array.

We can call linspace with endpoint set to False to remove the endpoint value.

And we get

[ 0. ,  0.1,  0.2,  0.3,  0.4,  0.5,  0.6,  0.7,  0.8,  0.9]

as a result.

Conclusion

To use a decimal range() step value with Python, we can use NumPy’s linspace method.