Added python solutions to encoding spaces.

arrays-strings/replace_char.ipynb

@@ -4,12 +4,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Problem: Given a String, Replace In-Place all Spaces with '%20'\n",
+    "## Problem: Given a string, replace in-place all spaces with '%20'\n",
     "\n",
     "* [Clarifying Questions](#Clarifying-Questions)\n",
     "* [Test Cases](#Test-Cases)\n",
     "* [Algorithm](#Algorithm)\n",
-    "* [Code](#Code)"
+    "* [Code](#Code)\n",
+    "* [Pythonic-Code: Not In-Place](#Pythonic-Code:-Not-In-Place)"
    ]
   },
   {
@@ -106,6 +107,32 @@
     "print(str2)\n",
     "print(str3)"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Pythonic-Code: Not In-Place\n",
+    "\n",
+    "The following code is Pythonic, but requires using additional data structures as Python strings are immutable.  You could use a bytearray or a list instead of a string to simulate manipulating an array of characters."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "import re\n",
+    "\n",
+    "def encode_spaces_alt(string):\n",
+    "    return re.sub(' ', '%20', string)\n",
+    "\n",
+    "def encode_spaces_alt2(string):\n",
+    "    return string.replace(' ', '%20')"
+   ]
   }
  ],
  "metadata": {