Here is another solution. There are probably a million ways to do this, so...

#!/usr/bin/perl -w

use strict;
use warnings;

my $TEXT = <<'END';
    >James
    >40
    >James
    >4
    >John
    >35
    >James
    >26
    >John
    >31
    >James
    >15
    >Pete
END

$TEXT =~ tr|a-zA-Z0-9||cd;        # Remove everything except letters a
+nd numbers

my @ARRAY = SplitNumbers($TEXT);  # Split numbers vs letters

if (@ARRAY & 1) { pop(@ARRAY); }  # Remove last element if it has no n
+umber following it.

my %HASH;                         # This is used as a global here

for (my $i = 0; $i < @ARRAY; $i+=2)
{
  if (exists($HASH{$ARRAY[$i]})) { $HASH{$ARRAY[$i]} .= ', '; }
  $HASH{$ARRAY[$i]} .= $ARRAY[$i+1];
}

print GetList('James');
print GetList('John');
print GetList('Pete');
print GetList('Bob');

exit;

##################################################
# Returns the named list in nicely formatted way.
#
# Usage: STRING = GetList(NAME)
#
sub GetList
{
  @_ or return '';
  my $NAME = shift;  # Get first argument, which is the 'NAME'

  return "\n   $NAME = [" . (exists($HASH{$NAME}) ? $HASH{$NAME} : '')
+ . "]\n";
}
##################################################
#
# Splits a string along numbers and returns an
# array of alternating numbers and text.
# Usage: ARRAY = SplitNumbers(STRING)
#
# Example: SplitNumbers('abc45tt-35203.19') -> ["abc", 45, "tt-", 3520
+3, ".", 19]
#
sub SplitNumbers
{
  defined $_[0] or return ();
  my ($PTR, $PREV, $LEN, $TYPE, @A) = (0, -1, length($_[0]));
  $LEN or return ();

# Possible values for $PREV: -1=Uninitialized 0=NUMBER 1=TEXT

  for (my $i = 0; $i < $LEN; $i++)
  {
    $TYPE = vec($_[0], $i, 8);
    $TYPE = $TYPE < 48 || $TYPE > 57;    # Is it a number?
    if ($PREV == !$TYPE)        # Same as before?
    {
      push(@A, substr($_[0], $PTR, $i-$PTR));
      $PTR = $i;
    }
    $PREV = $TYPE;
  }
  push(@A, substr($_[0], $PTR));    # Process last chunk
  return @A;
}
##################################################
[download]

This code outputs the following:

   James = [40, 4, 26, 15]

   John = [35, 31]

   Pete = []

   Bob = []
[download]