We write our "programming language" in Python3

1. Lexer

In this article we will do, so to speak, python2, create variables, output them to the console

If it comes to you, then I will do part 2 of the post: D

To begin with,
let's determine the name of the language - for example, “xnn”. Now create the xnn.py file and write the main code there:

import sys #  sys
import os #  os

dir = os.path.abspath(os.curdir) #   
p = str(dir) + '\\' + str(sys.argv[1]) #sys.argv[1] -  1 
print(p) #   +  
modules = ['if', 'else', 'while', 'for', '=', '==', '{', '}', '[', ']', '(', ')', '//'] #    
var = [] #   
vars_ = {} #   

with open(p, 'r', encoding="UTF-8") as f: #   
        for ex in f.read().split(): #  
            var.append(ex) #     var
    print(var) # $   $

What are we doing:

Import the os and sys libraries
Using os, we determine where the compiler is launched from (in the future I will tell you why)
Create the path to the file + take the file itself from the argument - we get it through sys.argv
Next, we display the path itself, with the file (in the future it will need to be deleted)
We create all the reserved words - for now, we don’t need it, but in the future we’ve got it for error output
Create lists for lexer and variables
We create the lexer itself, for this we open the file, in read mode, be sure to
encoding = "UTF-8"
if this is not done, then instead of Russian letters, there will be hieroglyphs!
Using for ex in read (). Split () we distribute all the text into words and put each word separately in ex
Next, write each word in the var list
And we will display the list itself - in the future it will be necessary to remove the output: /

Creating a .xnn File

Now we will create the file itself which we will parse, and also change the way of opening.

Open it and write it there:

pr = 
rprint pr

2. Creating a Compiler

Now create a compiler!
To do this, we supplement our file with code so that it turns out like this:

import sys #  sys
import os #  os

dir = os.path.abspath(os.curdir) #   
p = str(dir) + '\\' + str(sys.argv[1]) #sys.argv[1] -  1 
print(p) #   +  
modules = ['if', 'else', 'while', 'for', '=', '==', '{', '}', '[', ']', '(', ')', '//'] #    
var = [] #   
vars_ = {} #   
try:
    with open(p, 'r', encoding="UTF-8") as f: #   
        for ex in f.read().split(): #  
            var.append(ex) #     var
    print(var) # $   $
    a = -1 #     var
    for i in var: #  
        a = a + 1 #    
        if i == '=': #    "="
            vars_[var[a-1]] = var[a+1] #  vars_      "="
        if i == 'rprint':
            let = var[a+1]
            for key, value in vars_.items():
                if key == let:
                    print(value)
except FileNotFoundError:
    print('Error!   !')

What are we doing?

We iterate over all the values in var and when we find one or another reserved word, we do certain actions

Variable assignment

If i coincides with "=", add a value to the vars_ list , before "=" as key, and after "=" as value - thus forming a variable

Variable output

If i matches “rprint”, we look in the list vars_ for a match for this variable, which we get through our friend, the var list.
After finding, display the value of the variable

Work in action

In order to compile the file, enter the command data in cmd:

cd path/to/files
python xnn.py prog.xnn

The output is:

C:\Users\Hoopengo\Desktop\xnn\prog.xnn
['pr', '=', '', 'rprint', 'pr']

3. Compilation in .exe

Create a copy of the file folder and edit the xnn.py file

import sys #  sys
import os #  os

dir = os.path.abspath(os.curdir) #   
p = str(dir) + '\\' + str(sys.argv[1]) #sys.argv[1] -  1 
modules = ['if', 'else', 'while', 'for', '=', '==', '{', '}', '[', ']', '(', ')', '//'] #    
var = [] #   
vars_ = {} #   
try:
    with open(p, 'r', encoding="UTF-8") as f: #   
        for ex in f.read().split(): #  
            var.append(ex) #     var
    a = -1 #     var
    for i in var: #  
        a = a + 1 #    
        if i == '=': #    "="
            vars_[var[a-1]] = var[a+1] #  vars_      "="
        if i == 'rprint':
            let = var[a+1]
            for key, value in vars_.items():
                if key == let:
                    print(value)
except FileNotFoundError:
    print('Error!   !')

Install auto-py-to-exe
Complete installation information is available at this link.

Let's enter the console:

auto-py-to-exe

pip install auto-py-to-exe
auto-py-to-exe

The browser starts up. Choose the path to the file and One File there.

My Preset

4. Creating an installer

In the copied folder, create the bat.py file:

import os

with open('path\\xnn.exe', 'r', encoding='UTF-8') as f:
	lean = f.read()

	directory_folder = r"C:\\Windows\\System32\\xnn.exe"
	folder_path = os.path.dirname(directory_folder) #     

	if not os.path.exists(folder_path): #     
	    os.makedirs(folder_path)

	with open(directory_folder, 'w', encoding='UTF-8') as file: #    
	    file.write(lean)

After that, compile it into .exe and drop it into the same directory, it should look like this:

5. Installation

Now install.
To do this, open the file bat.exe, after which the installation will be done.
Restart the console and enter:

cd path/to/file
xnn prog.xnn

And we get:

If it says “xnn is not an internal command”, then add the xnn.exe file to the “C: \ Windows \ System32 \” folder yourself.

How to create a Python programming language?