Now in our earlier articles, we discussed the importance of programming and how to install python on your PC. Before starting with actual coding in Python, we should make ourselves familiar with certain programming terminologies that we will be using in our articles invariably. These are some of the most used words by any programmer you come across.
1) Program: A computer program is a collection of instructions given to perform a specific task. In general, any computer requires programs to function. These programs are processed by the center processing unit (CPU) of our laptops or PC.
2) Programming Languages: A programming language is a computer language which is designed to communicate the instructions that we code to the computer. It is due to these programming languages that we are able to write programs which can be executed by our computer. Example: C, C++, Java, Python, etc.
3) Character Set: Character set refers to the set of valid characters that a programming language can recognize. The following are the valid character set:
a) Letters: A – Z (Upper case alphabets), a – z (lower case alphabets)
b) Numbers: 0 – 9
c) Special symbols: +, *, /, _, %, &, etc.
d) White spaces: Blank space, Horizontal tabs, newline, etc.
e) Other ASCII characters: There are almost 256 ASCII characters
4) Compiler: A compiler is a program which translates high-level language program that is computer programs written using letters and digits into a machine language program. A compiler goes through the entire program at once and translates it into a machine code. It will check all kinds of limits, ranges, and errors in the program. Example: C++
5) Interpreter: Unlike compiler which translates the whole program into machine code, an interpreter translates only one statement of the program at a time. It reads one statement from the program, translates it then executes the statement. Then it will read next statement of the program, translates it and executes the statement. Example: Python
6) Token: The smallest individual unit in a given program is known as a token. Tokens are classified as follows:-
7) Keywords: Keywords are the words that convey special meaning to the programming language compiler. They are reserved to perform a specific task. As a good practice, you should not name your program based on these keywords. Example: if, else, while, for, class, etc.
8) Identifiers: In general identifiers are the names given to the unit of the program. Name of your script or module is identifiers. There is a rule that programmers follow to write an identifier. applies to most of the programming languages.
a) All identifiers must contain letters(That is it must have A – Z and a – z)
b) It can also have digits(0 – 9)
c) Special characters are not allowed while writing identifiers.
d) Underscore( _ ) qualifies as a letter and can be used while writing an identifier
e) The first character must be a letter
f) Identifiers are case sensitive. Thus upper and lower case letters are treated differently.
g) Example of some valid identifiers are Myfile, _CHK, Z2t0z\
Here are naming conventions for Python identifiers −
i) Class names start with an uppercase letter. All other identifiers start with a lowercase letter.
ii) Starting an identifier with a single leading underscore indicates that the identifier is private.
iii) Starting an identifier with two leading underscores indicates a strongly private identifier.
iv) If the identifier also ends with two trailing underscores, the identifier is a language-defined special name.
9) Data Types: Data types are the means to identify the types of data used in a programming language. With the help of data types, once we know the type of data, we can perform associated operations for handling the data. Example: integers (int), characters (char), floating points (float), double, etc.
10) Algorithms: Algorithms are a set of logical and mathematical procedures that one uses to solve a problem.
11) Control Flow: Control flows are the means to control the order in which a particular section of a code can be executed. They define a rule by which you can repeat this section of code.
12) Iteration: Iteration is a process to repeat a particular section of code to perform a certain action over and over again.
13) Syntax: Syntax refers to the structure of statements in a programming language. Getting syntax right is very important because as a programmer you can avoid a lot of errors in your code by following the correct syntax of a programming language.
14) Variables: In programming languages, a variable is a storage location with an associated name, an identifier, which can store some amount of information that we call as a value. So basically variables store values since they are storage locations and they have a name which is written according to the rules of writing an identifier. Example: Let’s say we have an integer variable with a name num and it stores a value 12 in it.
num = 12
15) Scripts: Since we will be learning Python so we will define scripts in reference to Python. A script is simply a python code or program.
16) Module: Modules are text files that contain our python statements or script.
17) Code Editors/Text Editor: Code Editors are software that makes programming easy. You cannot write codes in a word processor like Microsoft Word, Libre Writer or whatever you might be using. A code editor has line numbers to keep track of all the statements you write, this helps in rectifying errors in your code. Keywords in your code get highlighted in different colors. It helps to differentiate variables, reserved words, and logic of your code. Example: Atom, Notepad++, Sublime Text, etc.
18) Integrated Development Environment (IDE): Integrated Development Environment (IDE) is more advanced compared to a normal text editor. You can think it as a step up. An IDE has a code editor to write your source code and it has various tools to automate different tasks. An IDE these days have Code Editors, Compilers, Debuggers to check and fix errors, Build, access to code libraries, auto code completion, console or preview window to display your output, etc.
IDE is useful when working on projects with a large code base.
19) Bit: Binary Digit. That is, a variable quantity capable of holding exactly one of two possible values. By convention, these values are labeled 0 (zero) and 1 (one). A byte is 8 bits.
A kilobyte (KB) = 1024 bytes.
A megabyte (MB) = 1024 KB.
A gigabyte (GB) = 1024 MB.
A terabyte (TB) = 1024 GB.
A petabyte (PB) = 1024 TB.
An exabyte (EB) = 1024 PB.
20) Object: A contiguous region of memory with a type. First-class objects will perform all the “usual” operations, e.g., assignment. They are generally basic built-in types (int, double, float, boolean). Second-class objects (e.g., arrays) have special syntactical restrictions on their usage.