What is Python?

Python is a high-level scripting language that follows object-oriented programming principles. It is one the most easily understood languages as it often implements keywords written in English and doesn’t heavily rely on complex syntaxes and punctuated statements like other languages. It is an incredibly popular choice among programmers in the field of web development. Python can be the first-choice program for a beginner to master. Knowing some basic programming terminologies can go a long way in making Python an easy and fun language to grasp.

History of Python

Python was created by the Dutch programmer Guido van Rossum. During the time of its conception, it was meant to be a successor to the ABC programming language. It was developed to handle exceptions with the Amoeba operating system in mind. Later, after its release in 1991, it was treated as an automation language to fill the gaps within code. Additionally, it was also used to prototype software that was waiting to be implemented using another language. However, more recently, it has achieved the status of a general-purpose language. Now, Python is often found in applications of software development, machine learning, data analysis, web development, and much more.

Versions of Python

Python has two versions, both of which are slightly different. They are Python 2.x and 3.x. Before, there were a good amount of libraries supporting only Python 2. However, that number is slowly decreasing as more libraries are being implemented in version 3. For present-day coders, picking Python 3 is the best option. It has a new set of syntax functionalities and a robust interpreter. It also provides great support for concurrency controls.

Characteristics of Python

• As we know, Python is an object-oriented programming language. Therefore, it closely follows OOPs concepts such as class, object, encapsulation, polymorphism, message-passing, and abstraction.
• It has support for both functional programming (which means using functions as the building blocks of a program) and structured programming (which describes a program as a set of sequential steps to reach an end).
• It has a built-in automated garbage collection mechanism.
• Python was originally designed in C. Due to this, it has swift and seamless integration with C, C++, and Java.
• Python has utility as a scripting language to build much larger software.
• It allows the usage of many high-level data types.

Python Libraries

Python offers a predefined selection of code that executes a variety of tasks. These are called Python libraries. They take care of many actions such as mathematical operations, string handling, file input and output, multithreading, process management, and much more. These may be found in the Python Standard Library. Furthermore, Python has an intrinsic GUI library called Tkinter. Python also provides compatibility with third-party libraries in case the programmer’s desired operation is more specific. Some of the third party libraries, available through PyPi (Python Package Index) are NumPy for data visualization, Flask for web-related functionalities, and BeautifulSoup for HTML extraction.

Python Program Example

While in other programming languages, even a simple ‘hello world’ program requires a lot of syntactical compliances, like declaring the main function, adding curly braces, including preprocessor directives, and so on. But in Python, this program is just a single line:

print ( “Hello, world!”);

Let’s look at an example for determining if a number is prime or not.

var = 25

flag1 = False

if var > 1:

    for i in range(2, var):

        if (var % i) == 0:

             flag1 = True

            break

if flag1:

    print (var, "is not a prime number")

else:

    print (var, "is a prime number")

As we can see above, Python is not bound by any syntactical restrictions like other languages. There doesn’t seem to be any punctuation that the statements abide by. This program will display the result that ‘25’, contained in var, is not a prime number. The function range allows us to count the numbers between two specified numbers.

Common Mistakes in Python

While Python is easy to understand, even at beginner level, there are still a lot of possible mistakes that can trap a student or programmer trying their hand at the language for the first time. Some of them are:

• Issues with Error-handling: When Python code meets with an exception, a traceback is printed. A beginner may be easily overwhelmed by the output of a traceback, but understanding a traceback is essential to repair the exception thrown by the code. A traceback provides a ton of details on the type of exception a programmer is encountering.
• Mistakes in Indentation: To highlight the block of code an instruction is a part of, Python uses indentation. This makes the code appear legible. However, some errors in indentation are hard to capture in Python.  An example for such a case is the tangling of tabs and spaces.
• Static Tuple Values: In Python, if a tuple is built, the values that the tuple carries will become fixed. This can cause confusions among beginner programmers. However, a simple solution to rectify the static values in a tuple is to transform it to a list. Once a list is obtained, the values can be changed within it before it is converted back to a tuple.
• Expression Misuse: Function arguments can take on default values in Python. This can be a double-edged sword; while this is a good additional feature in a solid programming language like Python, a confusion occurs when a coder assumes that every time the function is mentioned, the optional variable to the function will take on the default value. But this is not the case; a value must be set to the optional variable.

Basic Features of Python

Built-in functions

A built-in function is coded in Python prior to the user writing any code, so that when it is called, it performs an action. Some common Python built-in functions are:

• print(): Outputs the program’s result for the programmer to see.
• pow(): Performs an exponential operation on a variable ‘a’ to the power of a variable ‘b’.
• min() and max(): In an iterable object, the minimum and maximum values are returned respectively.
• list(): Gives back a list in Python. Sometimes, this list can contain zero parameters (empty list).

Keywords

These are words that mean something within Python, and cannot be employed as variable names by a programmers. Some of the commonly seen keywords are:

• and, or, not: Represents the logical AND, OR, and NOT operators.
• class: Helps specify a class.
• for: States a for loop in the program.
• if, else: Both are used to set down a condition.
• True, False: Both are Boolean keywords used to perform comparisons based on conditions.
• while: States a while loop in the program
• None: Specifies a null value.

String operations

These functions perform operations on sequences of characters known as strings. Some of them are listed below:

• capitalize(): Turns the first letter of the string into upper case.
• casefold(): The string is transformed into lower-case characters.
• find(): Within a string, a value is searched for and its position is returned.
• isalpha(): Gives back Boolean value True if all the characters are alphabetical.
• islower(): Returns Boolean value True if string’s characters are in the lower case.

Similarly, there are methods to control and handle the Python dictionary, tuples, lists, file, exceptions, and so on.

Advantages of Python

• Easy use: Python is a highly readable and simple language with a humble collection of features. Programs don’t need to spend more time focusing on the syntax and can worry about problem-solving instead.
• Broad support: It can be used on all popular operating systems and platforms. Python is also easy to interface with many libraries.
• Constant updates: Python is constantly growing and changing so that it is on par with current software development procedures.

Disadvantages of Python

• Not suited for programs that are written at the fundamental system level (like kernels and drivers).
• If a standalone application is to be built across multiple platforms, Python is not the most elegant option.
• Python is a relatively slow language, so when speed is top-priority, Python is not recommended.

Applications of Python

• Data analytics and machine learning. In fact, it is the most popular high-level language for this purpose.
• General-purpose GUI applications and executables
• Services on the web.
• Python is efficient in building code generators (codes written in Python or even in other languages.

Context and Applications

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for 

• Bachelors in Computer Science 
• M.S in Computer Science