In today’s software industry, it is impossible to not know about the Python programming language. It has risen to an extreme standard, due to its simplicity of coding and human-readable code. Python is widely adapted in the scientific computing field, but it has also seen a tremendous amount of growth in the general software development industry.
Python had first introduced nearly three decades ago, but its widespread usage has been pretty recent. The article will help you understand the basic syntactic procedures and steps necessary for you to run a Python project successfully.
File Structure of Python Projects
Now let us first understand the file structure of a Python project. While working on industry level code, you would most probably come across code that is written in a hierarchy or form of various packages. So, it is necessary to understand what they are. While coding packages, it is crucial to remember that every hierarchy is decided and accessed by a dot (.), with the parent preceding the child package.
The second thing is the procedure in which Python gets executed. The subtle difference that most people fail to understand is that Python does get compiled. Yes, we do agree that Python is an interpreter language, but internally, Python does get compiled. It is one of the essential details to understand how to run a python project fully.
Python code is internally compiled into bytecode. But the CPU does not understand the Byte code generated. So, we need the interpreter. The interpreter is also called a Python virtual machine or PVM. So here are the internal steps executed, while trying to run a python project:
1. Syntax checker runs on the Python code
2. Internal compilation of the Python code
3. Conversion of Python code to Bytecode
4. Interpret the byte code via Python Virtual machine
5. Generate the output
If any error occurs at any step, the execution is interrupted on that line itself, and the error is printed. Due to this, some people find it difficult and tedious to solve errors in Python. In Python, the code may contain a hundred errors, but at a time, only one error is shown, as the execution gets halted at the line itself and prints the stack trace with the error message.
Installation and Setup of Python
Now before we start the implementation of our code, let us install and set up Python in our machine. The installation of Python is much simpler than most of the programming languages. To download Python on your PC, you may visit this site.
After downloading the Python executable file, just run it and it will install Python on your PC. If you use a Mac OS or Ubuntu-based operating system, then Python comes pre-installed. You can still verify by using the command Python in the terminal or command prompt.
Now let us write the first program in Python. Here is the starter code:
class firstPy: #class definition
def __init__(self, name): #internal function definition
self.name = name
def add(self,a,b): #function definition
print(“The sum is: “+str(a+b))
k = firstPy(“This”) #object creation
k.add(9,8) #calling function of the class firstPy
A lot of things are going on here. Let us discuss things one at a time.
The first thing to notice is the class definition. Most of the time, while you try to run a python project, it will contain a class, especially working with industry code. In python, the class is defined by keyword class followed by class name. In python, the blocks are defined by indentations.
While you try to run a python project, it is important to take care of that. Every internal block is indented. For example, the starting of the function inside the class needs to indent. Mostly, a tab works, but the standard definition also calls for four spaces. It is usually a personal preference.
Internal Function Definition
The second thing to note is the internal function definition. In python, the class initializer can be coded by __init__ function definition. Inside the class, functions are compulsory to have the ‘self’ argument. It is like the ‘this’ keyword that you may have noticed in other programming languages like C/C++.
Here we add a name parameter, to give our object a name at the time of creation. Whatever parameters are specified in the init keyword needs to be entered while the creation of the object of that particular class. Second is the add function.
Notice that this function also has a ‘self’ keyword parameter. The other two parameters are the numbers that will need adding up. The line of code following that does four things in total. First, computing the sum of a and b, which is done by the code snippet (a+b). The second is the str keyword. It converts the integer into the string.
Then the string concatenation takes place. And finally, the string is taken as an argument in the print statement, and the output is printed through that.
Now once the definitions are over, the time is to use those. The first thing is to create an instance of class firstPy. It can be done using the class name as a function call and initialize using the name attribute we added to its definition. It is crucial to assign the object to some variable, or else there is no way of accessing the functionality of it.
The next step is to use the add function inside the class firstPy. To access any internal function or variable, you can use the dot(.) functionality. So here we use k.add(9,8). Note that we are only supplying two arguments. The keyword self directly takes the object name as the argument. So, no need to explicitly pass the object to the ‘self’ parameter.
Check out: Python AI & ML Open Source Projects
Executing the Program
It is necessary to tell that the code is for Python3. It can be easily established, looking at the print statement. The print statement in Python2 does not have parenthesis.
Now, moving on to the execution of the program. You can type this up in any text editor of your choice and save the file with .py extension. For example, firstprogram.py. Once done, open the terminal in the file location and type the following command.
· python firstprogram.py
It will execute the program and should give the following output:
· The sum is: 17
Well, that is it. You successfully executed a program in Python. But how to run a python project? Specifically, a project.
Run a Python Project
Well, for this, first, you need to understand the structure of the project. If it is a minor project, you should be fine as it may not contain many files. But if it is a big project, there can be many .py files and, you may be confused as to which one to run.
Well, there is no clear choice in selecting a file. It depends on the documentation and how the project is coded. But mostly, the main file would be named accordingly. You only need to run that file with the same python command followed by the name of the file, and the code will execute itself if no errors occur.
While working on different projects and solving the errors or maybe adding new functionality, it is necessary to know and identify the structure of the project. For example, assume there is a project of a music classifier. It may contain many files, and some files may be arranged in the hierarchy of packages. It is critical to know which file is under which package or module. It can be seen and verified by looking at the folder structure as well as the first line of code in the file that is using that particular package.
It always contains the import keyword followed by the entire path hierarchy of the particular package in usage. Mostly, the packages are written, stored, and maintained in the hierarchy of folders itself, so it will not be much confusing to understand the modules. It is necessary to know this while trying to run a python project.
It is crucial to maintain the hierarchy in the same way it is written, or else you would need to use the functionality of a pre-built package “os”. The “os” package gives the function of joining the system path, which can help in importing packages out of the folder hierarchies.
Well, that is it about folder structure while running or coding a python project. We only have touched the surface of a python program, but it should help in understanding the structure of any python project that you try to run.
Also Read: Top 4 Python Challenges for Beginners
The Bottom Line
So, this is everything on how to run a python project. Python is a dynamic language. It has a huge community and a lot of pre-built functionalities that make the overall process of development smoother and way easier than other programming languages. It is important to note that sometimes Python may feel slow, especially on heavy computations but, the overall development speed makes up for it.
The development is easier also because of the ease of use of language and quick adaptability. Python is also reader-friendly. It is a bit easier to comb through a code written in Python than in other programming languages like C/C++.
To know more about the language and to learn more about it, do visit upGrad’s courses. upGrad also offers courses on scientific computation using Python, that is, the data science and machine learning algorithms. The knowledge you gained in the article will not only help in the general software development goals but also in courses and projects based on Data Science and ML or almost any other field in which Python is used.
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