clarify that dictionary keys are unique

Author: Rise Riyo

part-4.ipynb

@@ -1,7 +1,7 @@
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@@ -41,8 +41,7 @@
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@@ -61,8 +60,7 @@
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@@ -72,17 +70,7 @@
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-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 5,
-       "text": [
-        "[1, 1, 4, 9, 25, 64, 169, 441, 1156, 3025, 7921]"
-       ]
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-     ],
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@@ -106,8 +94,7 @@
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@@ -145,8 +132,7 @@
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@@ -166,8 +152,7 @@
      ],
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@@ -177,17 +162,7 @@
      ],
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      "metadata": {},
-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 17,
-       "text": [
-        "['Audrey', 'Alain']"
-       ]
-      }
-     ],
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+     "outputs": []
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@@ -204,8 +179,7 @@
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@@ -215,27 +189,17 @@
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      "metadata": {},
-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 19,
-       "text": [
-        "['Audrey', 'Alain']"
-       ]
-      }
-     ],
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       "## Dictionaries\n",
       "\n",
-      "Unlike lists, dictionaries are indexed by keys.  Dictionaries can be used to represent unordered key-value pairs.  Keys are used for lookup and their values are returned.\n",
+      "Unlike lists, dictionaries are indexed by keys.  Dictionaries can be used to represent unordered key-value pairs.  Keys are unique and are used for looking up values assigned to them.\n",
       "\n",
-      "Let's make an Spanish to English translator.  We'll ignore grammar and just translate word-by-word for now."
+      "Let's make a Spanish to English translator.  We'll ignore grammar and just translate word-by-word for now."
      ]
     },
     {