Functions - Crib Sheet

One of the key features of Python is its extensive library of built-in functions that make programming more efficient and convenient. In this article, we'll take an in-depth look at some of the most commonly used functions in Python and provide examples of how they are used.

print()

The print() function is used to output text to the console or terminal. It is one of the simplest and most commonly used functions in Python. The basic syntax of the print() function is as follows:

print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

Here, the objects parameter is the data that we want to print, sep is the separator between objects, end is the character that will be printed after the last object, file is the file object to which the output will be written, and flush is a Boolean value that determines whether the output buffer is flushed or not.

Example:

print("Hello, World!")

Output:

Hello, World!

len()

The len() function returns the length of an object. The object can be a string, list, tuple, dictionary, or any other sequence type. The syntax of the len() function is as follows:

len(s)

Here, s is the object whose length we want to find.

Example:

str = "Hello, World!" print(len(str))

Output:

13

range()

The range() function generates a sequence of numbers. It is often used in for loops to iterate over a sequence of numbers. The syntax of the range() function is as follows:

range(start, stop, step)

Here, start is the first number in the sequence (default is 0), stop is the last number in the sequence (not included), and step is the difference between each number in the sequence (default is 1).

Example:

for i in range(1, 11): print(i)

Output:

1 2 3 4 5 6 7 8 9 10

input()

The input() function is used to take user input from the console. The input is always in the form of a string. The syntax of the input() function is as follows:

input(prompt)

Here, prompt is the message that will be displayed to the user.

Example:

name = input("Enter your name: ") print("Hello, " + name + "!")

Output:

Enter your name: John Hello, John!

type()

The type() function is used to find the data type of an object. The syntax of the type() function is as follows:

type(object)

Here, object is the object whose data type we want to find.

Example:

x = 10 print(type(x))

Output:

<class 'int'>

str()

The str() function is used to convert an object into a string. The syntax of the str() function is as follows:

str(object)

Here, object is the object that we want to convert into a string.

Example:

x = 10 print(str(x))

Output:

10

int()

The int() function is used to convert a string or float into an integer. The syntax of the int() function is as follows:

int(x)

Here, x is the object that we want to convert into an integer.

x = "10" print(int(x))

Output:

10

float()

The float() function is used to convert a string or integer into a floating-point number. The syntax of the float() function is as follows:

float(x)

Here, x is the object that we want to convert into a floating-point number.

Example:

x = "10.5" print(float(x))

Output:

10.5

max()

The max() function is used to find the maximum value in an iterable object. The syntax of the max() function is as follows:

max(iterable, *iterables, key, default)

Here, iterable is the object whose maximum value we want to find, iterables are any other iterable objects that we want to include in the comparison, key is a function that takes an element as an argument and returns a value that will be used for comparison, and default is the value that will be returned if the iterable is empty.

Example:

numbers = [1, 5, 3, 7, 2] print(max(numbers))

Output:

7

min()

The min() function is used to find the minimum value in an iterable object. The syntax of the min() function is as follows:

min(iterable, *iterables, key, default)

Here, iterable is the object whose minimum value we want to find, iterables are any other iterable objects that we want to include in the comparison, key is a function that takes an element as an argument and returns a value that will be used for comparison, and default is the value that will be returned if the iterable is empty.

Example:

numbers = [1, 5, 3, 7, 2] print(min(numbers))

Output:

1

In conclusion, Python has a rich collection of built-in functions that make programming more efficient and convenient. This article covered some of the most commonly used functions, including print(), len(), range(), input(), type(), str(), int(), float(), max(), and min(). Understanding these functions is essential for any Python programmer, and mastering them will allow you to write more efficient and effective code.