Data commit

Task/Brace-expansion/Python/brace-expansion.py

@@ -0,0 +1,40 @@
+def getitem(s, depth=0):
+    out = [""]
+    while s:
+        c = s[0]
+        if depth and (c == ',' or c == '}'):
+            return out,s
+        if c == '{':
+            x = getgroup(s[1:], depth+1)
+            if x:
+                out,s = [a+b for a in out for b in x[0]], x[1]
+                continue
+        if c == '\\' and len(s) > 1:
+            s, c = s[1:], c + s[1]
+
+        out, s = [a+c for a in out], s[1:]
+
+    return out,s
+
+def getgroup(s, depth):
+    out, comma = [], False
+    while s:
+        g,s = getitem(s, depth)
+        if not s: break
+        out += g
+
+        if s[0] == '}':
+            if comma: return out, s[1:]
+            return ['{' + a + '}' for a in out], s[1:]
+
+        if s[0] == ',':
+            comma,s = True, s[1:]
+
+    return None
+
+# stolen cowbells from Raku example
+for s in '''~/{Downloads,Pictures}/*.{jpg,gif,png}
+It{{em,alic}iz,erat}e{d,}, please.
+{,{,gotta have{ ,\, again\, }}more }cowbell!
+{}} some }{,{\\\\{ edge, edge} \,}{ cases, {here} \\\\\\\\\}'''.split('\n'):
+    print "\n\t".join([s] + getitem(s)[0]) + "\n"