Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.5.4)
// ----

// padding and margin
$spacer: 1rem;
$spacers: ( 
  0: 0,
  1: ($spacer * .25),
  2: ($spacer * .5),
  3: $spacer,
  4: ($spacer * 2),
  5: ($spacer * 3),
  6: ($spacer * 4.5),
  7: ($spacer * 6.5)
);

$xy-border: (
  top: t, 
  bottom: b, 
  left: l, 
  right: r
);

// set solid borders
@each $direction in $xy-border {
  .border-#{nth($direction, 1)} {
    border-#{nth($direction, 1)}: 1px solid;
    border-color: grey;
  }
}

// padding and spacers
@each $prop, $letter in (margin: m, padding: p) { 
  @each $direction, $d in $xy-border {
    @each $unit, $rem in $spacers {
      .#{$letter}#{$d}-#{$unit} {
        #{$prop}-#{$direction}: #{$rem};
      }
      .#{$letter}x-#{$unit} {
        #{$prop}: 0 $rem;
      }
      .#{$letter}y-#{$unit} {
        #{$prop}: $rem 0;
      }
    }
  }
}

SassMeister-output.css

.border-top {
  border-top: 1px solid;
  border-color: grey;
}

.border-bottom {
  border-bottom: 1px solid;
  border-color: grey;
}

.border-left {
  border-left: 1px solid;
  border-color: grey;
}

.border-right {
  border-right: 1px solid;
  border-color: grey;
}

.mt-0 {
  margin-top: 0;
}

.mx-0 {
  margin: 0 0;
}

.my-0 {
  margin: 0 0;
}

.mt-1 {
  margin-top: 0.25rem;
}

.mx-1 {
  margin: 0 0.25rem;
}

.my-1 {
  margin: 0.25rem 0;
}

.mt-2 {
  margin-top: 0.5rem;
}

.mx-2 {
  margin: 0 0.5rem;
}

.my-2 {
  margin: 0.5rem 0;
}

.mt-3 {
  margin-top: 1rem;
}

.mx-3 {
  margin: 0 1rem;
}

.my-3 {
  margin: 1rem 0;
}

.mt-4 {
  margin-top: 2rem;
}

.mx-4 {
  margin: 0 2rem;
}

.my-4 {
  margin: 2rem 0;
}

.mt-5 {
  margin-top: 3rem;
}

.mx-5 {
  margin: 0 3rem;
}

.my-5 {
  margin: 3rem 0;
}

.mt-6 {
  margin-top: 4.5rem;
}

.mx-6 {
  margin: 0 4.5rem;
}

.my-6 {
  margin: 4.5rem 0;
}

.mt-7 {
  margin-top: 6.5rem;
}

.mx-7 {
  margin: 0 6.5rem;
}

.my-7 {
  margin: 6.5rem 0;
}

.mb-0 {
  margin-bottom: 0;
}

.mx-0 {
  margin: 0 0;
}

.my-0 {
  margin: 0 0;
}

.mb-1 {
  margin-bottom: 0.25rem;
}

.mx-1 {
  margin: 0 0.25rem;
}

.my-1 {
  margin: 0.25rem 0;
}

.mb-2 {
  margin-bottom: 0.5rem;
}

.mx-2 {
  margin: 0 0.5rem;
}

.my-2 {
  margin: 0.5rem 0;
}

.mb-3 {
  margin-bottom: 1rem;
}

.mx-3 {
  margin: 0 1rem;
}

.my-3 {
  margin: 1rem 0;
}

.mb-4 {
  margin-bottom: 2rem;
}

.mx-4 {
  margin: 0 2rem;
}

.my-4 {
  margin: 2rem 0;
}

.mb-5 {
  margin-bottom: 3rem;
}

.mx-5 {
  margin: 0 3rem;
}

.my-5 {
  margin: 3rem 0;
}

.mb-6 {
  margin-bottom: 4.5rem;
}

.mx-6 {
  margin: 0 4.5rem;
}

.my-6 {
  margin: 4.5rem 0;
}

.mb-7 {
  margin-bottom: 6.5rem;
}

.mx-7 {
  margin: 0 6.5rem;
}

.my-7 {
  margin: 6.5rem 0;
}

.ml-0 {
  margin-left: 0;
}

.mx-0 {
  margin: 0 0;
}

.my-0 {
  margin: 0 0;
}

.ml-1 {
  margin-left: 0.25rem;
}

.mx-1 {
  margin: 0 0.25rem;
}

.my-1 {
  margin: 0.25rem 0;
}

.ml-2 {
  margin-left: 0.5rem;
}

.mx-2 {
  margin: 0 0.5rem;
}

.my-2 {
  margin: 0.5rem 0;
}

.ml-3 {
  margin-left: 1rem;
}

.mx-3 {
  margin: 0 1rem;
}

.my-3 {
  margin: 1rem 0;
}

.ml-4 {
  margin-left: 2rem;
}

.mx-4 {
  margin: 0 2rem;
}

.my-4 {
  margin: 2rem 0;
}

.ml-5 {
  margin-left: 3rem;
}

.mx-5 {
  margin: 0 3rem;
}

.my-5 {
  margin: 3rem 0;
}

.ml-6 {
  margin-left: 4.5rem;
}

.mx-6 {
  margin: 0 4.5rem;
}

.my-6 {
  margin: 4.5rem 0;
}

.ml-7 {
  margin-left: 6.5rem;
}

.mx-7 {
  margin: 0 6.5rem;
}

.my-7 {
  margin: 6.5rem 0;
}

.mr-0 {
  margin-right: 0;
}

.mx-0 {
  margin: 0 0;
}

.my-0 {
  margin: 0 0;
}

.mr-1 {
  margin-right: 0.25rem;
}

.mx-1 {
  margin: 0 0.25rem;
}

.my-1 {
  margin: 0.25rem 0;
}

.mr-2 {
  margin-right: 0.5rem;
}

.mx-2 {
  margin: 0 0.5rem;
}

.my-2 {
  margin: 0.5rem 0;
}

.mr-3 {
  margin-right: 1rem;
}

.mx-3 {
  margin: 0 1rem;
}

.my-3 {
  margin: 1rem 0;
}

.mr-4 {
  margin-right: 2rem;
}

.mx-4 {
  margin: 0 2rem;
}

.my-4 {
  margin: 2rem 0;
}

.mr-5 {
  margin-right: 3rem;
}

.mx-5 {
  margin: 0 3rem;
}

.my-5 {
  margin: 3rem 0;
}

.mr-6 {
  margin-right: 4.5rem;
}

.mx-6 {
  margin: 0 4.5rem;
}

.my-6 {
  margin: 4.5rem 0;
}

.mr-7 {
  margin-right: 6.5rem;
}

.mx-7 {
  margin: 0 6.5rem;
}

.my-7 {
  margin: 6.5rem 0;
}

.pt-0 {
  padding-top: 0;
}

.px-0 {
  padding: 0 0;
}

.py-0 {
  padding: 0 0;
}

.pt-1 {
  padding-top: 0.25rem;
}

.px-1 {
  padding: 0 0.25rem;
}

.py-1 {
  padding: 0.25rem 0;
}

.pt-2 {
  padding-top: 0.5rem;
}

.px-2 {
  padding: 0 0.5rem;
}

.py-2 {
  padding: 0.5rem 0;
}

.pt-3 {
  padding-top: 1rem;
}

.px-3 {
  padding: 0 1rem;
}

.py-3 {
  padding: 1rem 0;
}

.pt-4 {
  padding-top: 2rem;
}

.px-4 {
  padding: 0 2rem;
}

.py-4 {
  padding: 2rem 0;
}

.pt-5 {
  padding-top: 3rem;
}

.px-5 {
  padding: 0 3rem;
}

.py-5 {
  padding: 3rem 0;
}

.pt-6 {
  padding-top: 4.5rem;
}

.px-6 {
  padding: 0 4.5rem;
}

.py-6 {
  padding: 4.5rem 0;
}

.pt-7 {
  padding-top: 6.5rem;
}

.px-7 {
  padding: 0 6.5rem;
}

.py-7 {
  padding: 6.5rem 0;
}

.pb-0 {
  padding-bottom: 0;
}

.px-0 {
  padding: 0 0;
}

.py-0 {
  padding: 0 0;
}

.pb-1 {
  padding-bottom: 0.25rem;
}

.px-1 {
  padding: 0 0.25rem;
}

.py-1 {
  padding: 0.25rem 0;
}

.pb-2 {
  padding-bottom: 0.5rem;
}

.px-2 {
  padding: 0 0.5rem;
}

.py-2 {
  padding: 0.5rem 0;
}

.pb-3 {
  padding-bottom: 1rem;
}

.px-3 {
  padding: 0 1rem;
}

.py-3 {
  padding: 1rem 0;
}

.pb-4 {
  padding-bottom: 2rem;
}

.px-4 {
  padding: 0 2rem;
}

.py-4 {
  padding: 2rem 0;
}

.pb-5 {
  padding-bottom: 3rem;
}

.px-5 {
  padding: 0 3rem;
}

.py-5 {
  padding: 3rem 0;
}

.pb-6 {
  padding-bottom: 4.5rem;
}

.px-6 {
  padding: 0 4.5rem;
}

.py-6 {
  padding: 4.5rem 0;
}

.pb-7 {
  padding-bottom: 6.5rem;
}

.px-7 {
  padding: 0 6.5rem;
}

.py-7 {
  padding: 6.5rem 0;
}

.pl-0 {
  padding-left: 0;
}

.px-0 {
  padding: 0 0;
}

.py-0 {
  padding: 0 0;
}

.pl-1 {
  padding-left: 0.25rem;
}

.px-1 {
  padding: 0 0.25rem;
}

.py-1 {
  padding: 0.25rem 0;
}

.pl-2 {
  padding-left: 0.5rem;
}

.px-2 {
  padding: 0 0.5rem;
}

.py-2 {
  padding: 0.5rem 0;
}

.pl-3 {
  padding-left: 1rem;
}

.px-3 {
  padding: 0 1rem;
}

.py-3 {
  padding: 1rem 0;
}

.pl-4 {
  padding-left: 2rem;
}

.px-4 {
  padding: 0 2rem;
}

.py-4 {
  padding: 2rem 0;
}

.pl-5 {
  padding-left: 3rem;
}

.px-5 {
  padding: 0 3rem;
}

.py-5 {
  padding: 3rem 0;
}

.pl-6 {
  padding-left: 4.5rem;
}

.px-6 {
  padding: 0 4.5rem;
}

.py-6 {
  padding: 4.5rem 0;
}

.pl-7 {
  padding-left: 6.5rem;
}

.px-7 {
  padding: 0 6.5rem;
}

.py-7 {
  padding: 6.5rem 0;
}

.pr-0 {
  padding-right: 0;
}

.px-0 {
  padding: 0 0;
}

.py-0 {
  padding: 0 0;
}

.pr-1 {
  padding-right: 0.25rem;
}

.px-1 {
  padding: 0 0.25rem;
}

.py-1 {
  padding: 0.25rem 0;
}

.pr-2 {
  padding-right: 0.5rem;
}

.px-2 {
  padding: 0 0.5rem;
}

.py-2 {
  padding: 0.5rem 0;
}

.pr-3 {
  padding-right: 1rem;
}

.px-3 {
  padding: 0 1rem;
}

.py-3 {
  padding: 1rem 0;
}

.pr-4 {
  padding-right: 2rem;
}

.px-4 {
  padding: 0 2rem;
}

.py-4 {
  padding: 2rem 0;
}

.pr-5 {
  padding-right: 3rem;
}

.px-5 {
  padding: 0 3rem;
}

.py-5 {
  padding: 3rem 0;
}

.pr-6 {
  padding-right: 4.5rem;
}

.px-6 {
  padding: 0 4.5rem;
}

.py-6 {
  padding: 4.5rem 0;
}

.pr-7 {
  padding-right: 6.5rem;
}

.px-7 {
  padding: 0 6.5rem;
}

.py-7 {
  padding: 6.5rem 0;
}

Problem with this code is that it does produce multiple mx/my and px/py classes. That is because of wrong use of nested loops. Use this code, where i nested loops little bit differently.

$spacer: 1rem;
$spacers: (
  1: ($spacer * .25),
  2: ($spacer * .5),
  3: $spacer,
  4: ($spacer * 2),
  5: ($spacer * 3),
);
$xy-border: ( top: t, right: r, bottom: b, left: l );


// padding and spacers
@each $prop, $letter in (margin: m, padding: p) { 
  @each $unit, $rem in $spacers {
        // For x and y is it sufficient to loop on this level.
        .#{$letter}x-#{$unit} {
          #{$prop}: 0 $rem;
        }
        .#{$letter}y-#{$unit} {
          #{$prop}: $rem 0;
        }
    @each $direction, $d in $xy-border {
      .#{$letter}#{$d}-#{$unit} {
        #{$prop}-#{$direction}: #{$rem};
      }
    }
  }
}

thanks for posting @PauliCZ44
i forgot about this gist; the production code for this changed years ago 😀

Handy gist. Using @PauliCZ44's update, I added negative margin classes that follow Bootstrap 5's naming convention:

$spacers: (
  1: ($spacer * .25),
  2: ($spacer * .5),
  3: $spacer,
  4: ($spacer * 2),
  5: ($spacer * 3),
);
$negative-spacers: (
  1: ($spacer * -.25),
  2: ($spacer * -.5),
  3: ($spacer * -1),
  4: ($spacer * -2),
  5: ($spacer * -3),
);
$xy-border: ( top: t, right: r, bottom: b, left: l );

// padding and margin classes
@each $prop, $letter in (margin: m, padding: p) { 
  @each $unit, $rem in $spacers {
        // For x and y is it sufficient to loop on this level.
    .#{$letter}x-#{$unit} {
          #{$prop}: 0 $rem;
        }
        .#{$letter}y-#{$unit} {
          #{$prop}: $rem 0;
        }
    @each $direction, $d in $xy-border {
      .#{$letter}#{$d}-#{$unit} {
        #{$prop}-#{$direction}: #{$rem};
      }
    }
  }
}

// negative margin classes
@each $prop, $letter in (margin: m) { 
  @each $unit, $rem in $negative-spacers {
        // For x and y is it sufficient to loop on this level.  
    .#{$letter}x-n#{$unit} {
      #{$prop}: 0 $rem;
    }
    .#{$letter}y-n#{$unit} {
      #{$prop}: $rem 0;
    }
    @each $direction, $d in $xy-border {
      .#{$letter}#{$d}-n#{$unit} {
        #{$prop}-#{$direction}: #{$rem};
      }
    }
  }
}

nice @peterankelein 😄