Using Python to enable camera without raspi-config

Question

I created a Python project that requires the camera to be enabled. In order to make it user friendly, I'm trying to enable the camera automatically without the user having to do it manually using raspi-config.

import configparser

def enable_camera():
    config_path = '/boot/config.txt'
    with open(config_path, 'r') as input_file:
        config_string = '[default]\n' + input_file.read()
    config = configparser.ConfigParser()
    config.read_string(config_string)
    config.set('default', 'start_x', '1')
    config.set('default', 'gpu_mem', '128')
    with open(config_path, 'w') as output_file:              
        config.write(output_file, space_around_delimiters=False)

After running the program this is the content of /boot/config/config.txt

[default]
dtparam=audio=on
start_x=1
gpu_mem=128
[pi4]
dtoverlay=vc4-fkms-v3d
max_framebuffers=2
[all]

Answer 1

I was able to fix this by writing a custom config parser which does not require having sections. I hope that it will be useful for other readers

class ConfigParser:
    
    def __init__(self, path, line_delimiter='=', comment_delimiter='#'):
        self.path = path
        self.line_delimiter = line_delimiter
        self.comment_delimiter = comment_delimiter
        self.lines = self.split()
        
    def validate_line(self, line):
        return not line.strip().startswith(self.comment_delimiter) and line.count(self.line_delimiter) == 1
    
    def split(self):
        with open(self.path, 'r') as f:
            return f.read().splitlines()
        
    def set(self, key, value):
        flag = False
        for i in range(0, len(self.lines)):
            line = self.lines[i].replace(' ', '')
            if self.validate_line(line):
                k, v = line.split(self.line_delimiter)
                if key == k:
                    self.lines[i] = k + self.line_delimiter + value
                    flag = True
                    break
        if not flag:
            self.lines.append(key + self.line_delimiter + value)
                    
    def get(self, key):
        for i in range(0, len(self.lines)):
            line = self.lines[i].replace(' ', '')
            if self.validate_line(line):
                k, v = line.split(self.line_delimiter)
                if key == k:
                    return v
                
    def write(self, path):
        with open(path, 'w') as f:
            for line in self.lines:
                f.write("%s\n" % line)


if __name__ == '__main__':
    config = ConfigParser('config.txt')
    config.set('start_x', '1')
    config.set('gpu_mem', '128')
    config.write('config2.txt')

By default set() and get() ignore comments and only keep valid lines (key=value)