Category: Python Answers

Sometimes, we want to add static methods in Python classes.

In this article, we’ll look at how to add static methods in Python classes.

How to add static methods in Python classes?

To add static methods in Python classes, we use the @staticmethod decorator.

For instance, we write:

class C:
    @staticmethod
    def f():
      print('static')

C.f()      

We make f a static method with the @staticmethod decorator.

Then we call C.f dirertly without instantiating C.

Therefore, we see 'static' printed.

Conclusion

To add static methods in Python classes, we use the @staticmethod decorator.

Sometimes, we want to remove an element from a list by index with Python.

In this article, we’ll look at how to remove an element from a list by index with Python.

How to remove an element from a list by index with Python?

To remove an element from a list by index with Python, we can use the del operator.

For instance, we write:

a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
del a[-1]
print(a)

to remove the last element by passing in index -1 into the square brackets.

Therefore, a is [0, 1, 2, 3, 4, 5, 6, 7, 8] after del is used.

We can also use del to remove elements from the starting index to the ending index minus one.

For instance, we write:

a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
del a[2:4]
print(a)

to remove elements from a with index 2 and 3.

Therefore, a is [0, 1, 4, 5, 6, 7, 8, 9] after del is used.

Conclusion

To remove an element from a list by index with Python, we can use the del operator.

Sometimes, we want to print literal curly-brace characters in a string and also use .format it with Python.

In this article, we’ll look at how to print literal curly-brace characters in a string and also use .format it with Python.

How to print literal curly-brace characters in a string and also use .format it with Python?

To print literal curly-brace characters in a string and also use .format it with Python, we can use double curly braces in the string.

For instance, we write:

x = " {{ Hello }} {0} "
print(x.format('jane'))

to surround ‘Hello’ with double curly braces, which will be return a string with single curly braces surround it.

Therefore, we get ' { Hello } jane ' returned and printed.

Conclusion

To print literal curly-brace characters in a string and also use .format it with Python, we can use double curly braces in the string.

Sometimes, we want to limit floats to two decimal points with Python.

In this article, we’ll look at how to limit floats to two decimal points with Python.

How to limit floats to two decimal points with Python?

To limit floats to two decimal points with Python, we can use the format function.

For instance, we write:

a = 13.949999999999999
b = format(a, '.2f')
print(b)

to call format with number a, and '.2f' to return a rounded to 2 decimal places.

And we assign the returned result to b.

Therefore, b is 13.95.

Conclusion

To limit floats to two decimal points with Python, we can use the format function.

Sometimes, we want to make a time delay in Python.

In this article, we’ll look at how to make a time delay in Python.

How to make a time delay in Python?

To make a time delay in Python, we can use the sleep function from the time module.

For instance, we write:

from time import sleep
print('foo')
sleep(0.1) 
print('bar')

We call the sleep with the number of seconds to pause the program for.

Conclusion

To make a time delay in Python, we can use the sleep function from the time module.