Category: Python Answers

Sometimes, we want to check if a float value is a whole number with Python.

In this article, we’ll look at how to check if a float value is a whole number with Python.

How to check if a float value is a whole number with Python?

To check if a float value is a whole number with Python, we can use the float’s is_integer method.

For instance, we write:

print((1.0).is_integer())
print((1.5).is_integer())

We call is_integer on 2 floats and print out the values.

Since 1.0 is an integer, the first print will print True.

And since 1.5 isn’t an integer, the 2nd print will print False.

Conclusion

To check if a float value is a whole number with Python, we can use the float’s is_integer method.

Sometimes, we want to create nice column output in Python.

In this article, we’ll look at how to create nice column output in Python.

How to create nice column output in Python?

To create nice column output in Python, we can use format strings with print.

For instance, we write:

table_data = [['a', 'b', 'c'], ['aa', 'b', 'c'], ['a', 'bb', 'c']]
for row in table_data:
    print("{: >20} {: >20} {: >20}".format(*row))

We use the {: >20} to set each column to have at least 20 characters and align the text to the right.

Therefore, we get:

                   a                    b                    c
                  aa                    b                    c
                   a                   bb                    c

from the print output.

Conclusion

To create nice column output in Python, we can use format strings with print.

Sometimes, we want to unzip files with Python.

In this article, we’ll look at how to unzip files with Python.

How to unzip files with Python?

To unzip files with Python, we can use the zipfile module.

For instance, we write:

import zipfile

path_to_zip_file = 'test.zip'
directory_to_extract_to = './test'

with zipfile.ZipFile(path_to_zip_file, 'r') as zip_ref:
    zip_ref.extractall(directory_to_extract_to)

We read the zip file into a Python object with zipfile.ZipFile(path_to_zip_file, 'r').

Then we call extractall on the returned zip file object to do the extraction.

We specify the directory_to_extract_to to extract the zip file’s contents.

Now we should see the test folder having the content of the zip file after the code is run.

Conclusion

To unzip files with Python, we can use the zipfile module.

Sometimes, we want to get the number of elements in a list with Python.

In this article, we’ll look at how to get the number of elements in a list with Python.

How to get the number of elements in a list with Python?

To get the number of elements in a list with Python, we can use the len function.

For instance, we write:

l = len([1, 2, 3])
print(l)

We call len with a list as its argument to return the number of items in the list and assign that to l.

Therefore, l is 3.

Conclusion

To get the number of elements in a list with Python, we can use the len function.

Sometimes, we want to print all instances of a class with Python.

In this article, we’ll look at how to print all instances of a class with Python.

How to print all instances of a class with Python?

To print all instances of a class with Python, we can use the gc module.

For instance, we write:

import gc


class A:
    pass


a1 = A()
a2 = A()
for obj in gc.get_objects():
    if isinstance(obj, A):
        print(obj)

We have the A class and we create 2 instances of it, which we assigned to a1 and a2.

Then we loop through the objects in memory with gc.get_objects with a for loop.

And we check if each obj is an instance of A with isinstance.

If it is, we print it.

Therefore, we see:

<__main__.A object at 0x7f36601f5b80>
<__main__.A object at 0x7f36601f57c0>

from the print output.

Conclusion

To print all instances of a class with Python, we can use the gc module.