Godbolt does Python! (And lots of other languages…)

Python

import cmath

# Calculate if each point in an x-y plane "escapes" the shape
for y in range(-10, 10):
    for x in range(-40, +40):

        # Initialise the calculation
        z = 0

        # Create a complex number based on current coordinates
        # Note the fudge factor of 2 because characters are taller than high
        c = complex(x / 20.0, y / 10.0)

        # Check if calculation remains bounded (stays on the page)
        for _ in range(30):

            # THE IMPORTANT BIT!
            # https://en.wikipedia.org/wiki/Mandelbrot_set

            z = pow(z, 2) + c

            # These numbers can get pretty big very quickly
            # So quit the loop if the result is already off the page
            if abs(z) > 2:
              break

        # Print this point
        print(chr(int(abs(z) <= 2) + 32), end="") 

    # Print a New line at the end of each row
    print("")
                                        !                                       
                                     !                                          
                                    !!!!                                        
                                    !!!!                                        
                             !!  !!!!!!!!!!                                     
                             !!!!!!!!!!!!!!!!!!                                 
                            !!!!!!!!!!!!!!!!!!!                                 
                    !      !!!!!!!!!!!!!!!!!!!!!                                
                 !!!!!!!  !!!!!!!!!!!!!!!!!!!!!!!                               
                !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!                                
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!                                  
                !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!                                
                 !!!!!!!  !!!!!!!!!!!!!!!!!!!!!!!                               
                    !      !!!!!!!!!!!!!!!!!!!!!                                
                            !!!!!!!!!!!!!!!!!!!                                 
                             !!!!!!!!!!!!!!!!!!                                 
                             !!  !!!!!!!!!!                                     
                                    !!!!                                        
                                    !!!!                                        
                                     !                                          

https://godbolt.org/z/c4sG1Yx4P

C++

#include <complex>
#include <fmt/core.h>
#include <numeric>
#include <ranges>

int main() {
  for (const auto y : std::views::iota(-15, 15)) {
    for (const auto x : std::views::iota(-20, 70)) {

      auto z = std::complex(0.0, 0.0);
      const auto c = std::complex((x / 25.0) - 2, y / 10.0);

      for (auto i = size_t{0}; i < 30; ++i) {

        z = z * z + c;

        if (std::abs(z) > 2.0)
          break;
      }

      fmt::print("{}", std::abs(z) < 2.0 ? "0" : " ");
    }

    fmt::print("\n");
  }
}
                                                                      0                   
                                                                   0                      
                                                                 00000                    
                                                                 00000                    
                                                        000  0000000000000                
                                                         0000000000000000000000           
                                                      0000000000000000000000000           
                                         00  0       000000000000000000000000000          
                                         000000000  00000000000000000000000000000         
                                        0000000000000000000000000000000000000000          
                     00000000000000000000000000000000000000000000000000000000             
                                        0000000000000000000000000000000000000000          
                                         000000000  00000000000000000000000000000         
                                         00  0       000000000000000000000000000          
                                                      0000000000000000000000000           
                                                         0000000000000000000000           
                                                        000  0000000000000                
                                                                 00000                    
                                                                 00000                    
                                                                   0                      
                                                                      0                   

https://godbolt.org/z/jMe5b8shh