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Author: khuyentran1401

Chapter2/itertools.ipynb

@@ -654,67 +654,82 @@
    "id": "16243084",
    "metadata": {},
    "source": [
-    "### itertools.dropwhile: Drop Elements in an Iterable Until a Condition Is False"
+    "### Python's dropwhile: A Clean Approach to Sequential Filtering"
    ]
   },
   {
-   "attachments": {},
    "cell_type": "markdown",
-   "id": "b5d8c554",
+   "id": "095d11d6-df75-464a-9623-cee19e91b4b6",
    "metadata": {},
    "source": [
-    "If you want to drop elements from an iterable until a condition is false, use `itertools.dropwhile`."
+    "Repeatedly checking elements in an iteration until a condition is met results in verbose and less readable code, especially when you want to skip elements at the beginning of a sequence."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
-   "id": "cd9d5db3",
+   "execution_count": 8,
+   "id": "e68b75f2-97cb-445d-938e-1d7e3dc54222",
    "metadata": {},
    "outputs": [
     {
-     "data": {
-      "text/plain": [
-       "[5, 2, 4]"
-      ]
-     },
-     "execution_count": 12,
-     "metadata": {},
-     "output_type": "execute_result"
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ABC456\n"
+     ]
     }
    ],
    "source": [
-    "from itertools import dropwhile\n",
+    "text = \"123ABC456\"\n",
+    "alpha_part = []\n",
+    "found_alpha = False\n",
     "\n",
-    "nums = [1, 2, 5, 2, 4]\n",
+    "for char in text:\n",
+    "    if found_alpha or not char.isdigit():\n",
+    "        found_alpha = True\n",
+    "        alpha_part.append(char)\n",
     "\n",
-    "# Drop every number until a number >= 5\n",
-    "list(dropwhile(lambda n: n < 5, nums))"
+    "\n",
+    "print(''.join(alpha_part))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9fff7ed4-d7f6-4862-934d-61bfa1728a89",
+   "metadata": {},
+   "source": [
+    "With `itertools.dropwhile`, you can elegantly skip elements from the beginning of an iteration until a condition becomes False, making your code more concise and functional."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
-   "id": "e29b4c7f",
+   "execution_count": 7,
+   "id": "a1464951-36c2-4086-8647-dd388633bfb9",
    "metadata": {},
    "outputs": [
     {
-     "data": {
-      "text/plain": [
-       "'Nice!'"
-      ]
-     },
-     "execution_count": 13,
-     "metadata": {},
-     "output_type": "execute_result"
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "ABC456\n"
+     ]
     }
    ],
    "source": [
-    "word = 'abcNice!'\n",
+    "from itertools import dropwhile\n",
+    "\n",
+    "text = \"123ABC456\"\n",
+    "alpha_part = dropwhile(str.isdigit, text)\n",
     "\n",
-    "# Drop every char until a char is in upper case\n",
-    "chars  = dropwhile(lambda char: char.islower(), word)\n",
-    "''.join(chars)"
+    "print(''.join(alpha_part))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "e7b1b11a-97b0-4a2e-9e78-4ceed235d52a",
+   "metadata": {},
+   "source": [
+    "In this example, `dropwhile` takes a predicate function (`str.isdigit`) and the text string. It skips digits until it finds a non-digit character, then returns the rest of the string. "
    ]
   },
   {