A commented solution in Python

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diff --git a/challenge-134/dave-jacoby/python/ch-1.py b/challenge-134/dave-jacoby/python/ch-1.py
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+#!/usr/bin/env python3
+
+# would want to pass an array reference, but 
+# haven't found how you can do that in Python.
+# It might not be possible.
+output=[]
+
+def main():
+    pandigital()
+
+def pandigital():
+    # because we see 0123 as 123, we cannot start
+    # with 0, so we force the issue by starting with 
+    # one
+    state=["1"]
+    _pandigital(state)
+    for o in output:
+        print( o )
+
+def _pandigital(state):
+    # we're dumping to a global array 
+    # so we can know when we've hit five
+    # and can just bail
+    if len(output)>4:
+        return
+    # if length is 10, we've used all the
+    # digits and can convert the array of
+    # digits into a number and append that
+    # to output
+    if len(state)==10:
+        pandigital = int("".join(list(state)))
+        output.append(pandigital)
+        return
+    # dicts are like hashes and useful to 
+    # keep you from using the same thing twice
+    # (asterisk)
+    mydict = {}
+    numbers = []
+    # thing is, join wants a string, so we have
+    # to always treat the digits as strings, and
+    # so we must cast to string before adding to
+    # the dictionary
+    for n in state:
+        mydict[str(n)] = 1
+    # and also here, so we know that once we've
+    # used 0, we don't use it again
+    for n in range(10):
+        if str(n) not in mydict:
+            numbers.append(str(n))
+    # and here, we copy the current state array,
+    # append what numbers we have, and recurse
+    for n in numbers:
+        newstate = state.copy()
+        newstate.append(n)
+        _pandigital(newstate)
+    return 
+
+if __name__ == '__main__':
+    main()
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