diff --git a/01.01 python 基础.ipynb b/01.01 python 基础.ipynb
index a0a6950..529b05c 100644
--- a/01.01 python 基础.ipynb
+++ b/01.01 python 基础.ipynb
@@ -34,7 +34,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (\"hello world!\")"
+    "print(\"hello world!\")"
    ]
   },
   {
@@ -149,8 +149,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (min(2, 3, 4, 5))\n",
-    "print (max(2, 4, 3))"
+    "print(min(2, 3, 4, 5))\n",
+    "print(max(2, 4, 3))"
    ]
   },
   {
@@ -167,7 +167,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (int(-3.32))"
+    "print(int(-3.32))"
    ]
   },
   {
@@ -183,7 +183,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (float(1))"
+    "print(float(1))"
    ]
   },
   {
@@ -239,7 +239,7 @@
    "outputs": [],
    "source": [
     "s = \"hello, world\"\n",
-    "print (s)"
+    "print(s)"
    ]
   },
   {
@@ -249,7 +249,7 @@
    "outputs": [],
    "source": [
     "s = 'hello, world'\n",
-    "print (s)"
+    "print(s)"
    ]
   },
   {
@@ -305,7 +305,7 @@
    "source": [
     "line = \"1 2 3 4  5\"\n",
     "numbers = line.split()\n",
-    "print (numbers)\n",
+    "print(numbers)\n",
     "type(numbers)"
    ]
   },
@@ -372,10 +372,10 @@
    "outputs": [],
    "source": [
     "s = \"HELLO WORLD\"\n",
-    "print (s.lower())\n",
+    "print(s.lower())\n",
     "\n",
     "# 不会改变原来s的值\n",
-    "print (s)"
+    "print(s)"
    ]
   },
   {
@@ -488,7 +488,7 @@
    "outputs": [],
    "source": [
     "l = [1, 2.0, 'hello']\n",
-    "print (l)"
+    "print(l)"
    ]
   },
   {
@@ -646,7 +646,7 @@
    "source": [
     "a = [10, 11, 12]\n",
     "a.append(11)\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -664,7 +664,7 @@
    "source": [
     "a = [10, 11, 12]\n",
     "a.append(['a', 'b'])\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -683,7 +683,7 @@
    "source": [
     "a = [10, 11, 12]\n",
     "a.extend(['a', 'b'])\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -703,7 +703,7 @@
     "a = [10, 11, 12, 13, 11]\n",
     "# 在索引 3 插入 'a'\n",
     "a.insert(3, 'a')\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -729,7 +729,7 @@
     "# 根据下标进行删除\n",
     "a = [1002, 'a', 'b', 'c']\n",
     "del a[0]\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -748,7 +748,7 @@
    "source": [
     "a = [1002, 'a', 'b', 'c']\n",
     "a.pop()\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -767,7 +767,7 @@
    "source": [
     "a = [1002, 'a', 'b', 'c', 'b']\n",
     "a.remove(\"b\")\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -787,8 +787,8 @@
    "outputs": [],
    "source": [
     "a = [10, 11, 12, 13, 11]\n",
-    "print (10 in a)\n",
-    "print (10 not in a)"
+    "print(10 in a)\n",
+    "print(10 not in a)"
    ]
   },
   {
@@ -870,7 +870,7 @@
     "# 从小到大排序\n",
     "a = [10, 1, 11, 13, 11, 2]\n",
     "a.sort()\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -882,7 +882,7 @@
     "# 从大到小排序\n",
     "a = [10, 1, 11, 13, 11, 2]\n",
     "a.sort(reverse=True)\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -900,8 +900,8 @@
    "source": [
     "a = [10, 1, 11, 13, 11, 2]\n",
     "b = sorted(a)\n",
-    "print (\"a:\",a)\n",
-    "print (\"b:\",b)"
+    "print(\"a:\",a)\n",
+    "print(\"b:\",b)"
    ]
   },
   {
@@ -926,7 +926,7 @@
    "source": [
     "a = [10, 1, 11, 13, 11, 2]\n",
     "a.reverse()\n",
-    "print (a)"
+    "print(a)"
    ]
   },
   {
@@ -944,8 +944,8 @@
    "source": [
     "a = [10, 1, 11, 13, 11, 2]\n",
     "b = a[::-1]\n",
-    "print (\"a:\",a)\n",
-    "print (\"b:\",b)"
+    "print(\"a:\",a)\n",
+    "print(\"b:\",b)"
    ]
   },
   {
@@ -1312,8 +1312,8 @@
    "source": [
     "x = 0.5\n",
     "if x > 0:\n",
-    "    print (\"Hey!\")\n",
-    "    print (\"x is positive\")"
+    "    print(\"Hey!\")\n",
+    "    print(\"x is positive\")"
    ]
   },
   {
@@ -1348,10 +1348,10 @@
    "source": [
     "x = 0.5\n",
     "if x > 0:\n",
-    "    print (\"Hey!\")\n",
-    "    print (\"x is positive\")\n",
-    "    print (\"This is still part of the block\")\n",
-    "print (\"This isn't part of the block, and will always print.\")"
+    "    print(\"Hey!\")\n",
+    "    print(\"x is positive\")\n",
+    "    print(\"This is still part of the block\")\n",
+    "print(\"This isn't part of the block, and will always print.\")"
    ]
   },
   {
@@ -1369,10 +1369,10 @@
    "source": [
     "x = -0.5\n",
     "if x > 0:\n",
-    "    print (\"Hey!\")\n",
-    "    print (\"x is positive\")\n",
-    "    print (\"This is still part of the block\")\n",
-    "print (\"This isn't part of the block, and will always print.\")\n"
+    "    print(\"Hey!\")\n",
+    "    print(\"x is positive\")\n",
+    "    print(\"This is still part of the block\")\n",
+    "print(\"This isn't part of the block, and will always print.\")\n"
    ]
   },
   {
@@ -1404,11 +1404,11 @@
    "source": [
     "x = 0\n",
     "if x > 0:\n",
-    "    print (\"x is positive\")\n",
+    "    print(\"x is positive\")\n",
     "elif x == 0:\n",
-    "    print (\"x is zero\")\n",
+    "    print(\"x is zero\")\n",
     "else:\n",
-    "    print (\"x is negative\")\n"
+    "    print(\"x is negative\")\n"
    ]
   },
   {
@@ -1466,12 +1466,12 @@
    "source": [
     "year = 1900\n",
     "if year % 400 == 0:\n",
-    "    print (\"This is a leap year!\")\n",
+    "    print(\"This is a leap year!\")\n",
     "# 两个条件都满足才执行\n",
     "elif year % 4 == 0 and year % 100 != 0:\n",
-    "    print (\"This is a leap year!\")\n",
+    "    print(\"This is a leap year!\")\n",
     "else:\n",
-    "    print (\"This is not a leap year.\")\n"
+    "    print(\"This is not a leap year.\")\n"
    ]
   },
   {
@@ -1503,9 +1503,9 @@
    "source": [
     "mylist = [3, 1, 4, 1, 5, 9]\n",
     "if mylist:\n",
-    "    print (\"The first element is:\", mylist[0])\n",
+    "    print(\"The first element is:\", mylist[0])\n",
     "else:\n",
-    "    print (\"There is no first element.\")"
+    "    print(\"There is no first element.\")"
    ]
   },
   {
@@ -1523,9 +1523,9 @@
    "source": [
     "mylist = []\n",
     "if mylist:\n",
-    "    print (\"The first element is:\", mylist[0])\n",
+    "    print(\"The first element is:\", mylist[0])\n",
     "else:\n",
-    "    print (\"There is no first element.\")\n"
+    "    print(\"There is no first element.\")\n"
    ]
   },
   {
@@ -1563,15 +1563,13 @@
     "\n",
     "# 循环条件\n",
     "while i < 100:\n",
-    "    \n",
     "    # 求和累加\n",
     "    total += i\n",
-    "    \n",
     "    # 变量递增\n",
     "    i += 1\n",
     "    \n",
     "# 打印结果\n",
-    "print (total)"
+    "print(total)"
    ]
   },
   {
@@ -1590,7 +1588,7 @@
     "plays = ['Hamlet', 'Macbeth', 'King Lear']\n",
     "while plays:\n",
     "    play = plays.pop()\n",
-    "    print ('Perform', play)"
+    "    print('Perform', play)"
    ]
   },
   {
@@ -1622,7 +1620,7 @@
    "source": [
     "plays = ['Hamlet', 'Macbeth', 'King Lear']\n",
     "for play in plays:\n",
-    "    print ('Perform', play)"
+    "    print('Perform', play)"
    ]
   },
   {
@@ -1643,7 +1641,7 @@
     "total = 0\n",
     "for i in range(100):\n",
     "    total += i\n",
-    "print (total)"
+    "print(total)"
    ]
   },
   {
@@ -1668,7 +1666,7 @@
     "    if i % 2 != 0:\n",
     "        # 忽略奇数\n",
     "        continue\n",
-    "    print (i/2)"
+    "    print(i/2)"
    ]
   },
   {
@@ -1731,10 +1729,10 @@
     "values = [7, 6, 4, 7, 19, 2, 1]\n",
     "for x in values:\n",
     "    if x <= 10:\n",
-    "        print ('Found:', x)\n",
+    "        print('Found:', x)\n",
     "        break\n",
     "else:\n",
-    "    print ('All values greater than 10')\n"
+    "    print('All values greater than 10')\n"
    ]
   },
   {
@@ -1753,10 +1751,10 @@
     "values = [11, 12, 13, 100]\n",
     "for x in values:\n",
     "    if x <= 10:\n",
-    "        print ('Found:', x)\n",
+    "        print('Found:', x)\n",
     "        break\n",
     "else:\n",
-    "    print ('All values greater than 10')\n"
+    "    print('All values greater than 10')\n"
    ]
   }
  ],
diff --git a/01.02 python 进阶.ipynb b/01.02 python 进阶.ipynb
index 69c6dbd..577197a 100644
--- a/01.02 python 进阶.ipynb
+++ b/01.02 python 进阶.ipynb
@@ -173,8 +173,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(2, 3))\n",
-    "print (add('foo', 'bar'))"
+    "print(add(2, 3))\n",
+    "print(add('foo', 'bar'))"
    ]
   },
   {
@@ -190,7 +190,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(2, \"foo\"))"
+    "print(add(2, \"foo\"))"
    ]
   },
   {
@@ -222,8 +222,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(x=2, y=3))\n",
-    "print (add(y=\"foo\", x=\"bar\"))"
+    "print(add(x=2, y=3))\n",
+    "print(add(y=\"foo\", x=\"bar\"))"
    ]
   },
   {
@@ -239,7 +239,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(2, y=3))"
+    "print(add(2, y=3))"
    ]
   },
   {
@@ -274,7 +274,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (quad(2.0))"
+    "print(quad(2.0))"
    ]
   },
   {
@@ -290,16 +290,16 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (quad(2.0, b=3))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "print (quad(2.0, 2, c=4))"
+    "print(quad(2.0, b=3))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "print(quad(2.0, 2, c=4))"
    ]
   },
   {
@@ -317,7 +317,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (quad(2.0, 2, a=2))"
+    "print(quad(2.0, 2, a=2))"
    ]
   },
   {
@@ -355,8 +355,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(1, 2, 3, 4))\n",
-    "print (add(1, 2))\n"
+    "print(add(1, 2, 3, 4))\n",
+    "print(add(1, 2))\n"
    ]
   },
   {
@@ -375,7 +375,7 @@
     "def add(x, **kwargs):\n",
     "    total = x\n",
     "    for arg, value in kwargs.items():\n",
-    "        print (\"adding %s=%s\"%(arg,value))\n",
+    "        print(\"adding %s=%s\"%(arg,value))\n",
     "        total += value\n",
     "    return total\n"
    ]
@@ -393,7 +393,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (add(10, y=11, z=12, w=13))"
+    "print(add(10, y=11, z=12, w=13))"
    ]
   },
   {
@@ -410,7 +410,7 @@
    "outputs": [],
    "source": [
     "def foo(*args, **kwargs):\n",
-    "    print (args, kwargs)\n",
+    "    print(args, kwargs)\n",
     "\n",
     "foo(2, 3, x='bar', z=10)\n"
    ]
@@ -488,7 +488,7 @@
    "outputs": [],
    "source": [
     "a, b, c = [1, 2, 3]\n",
-    "print (a, b, c)"
+    "print(a, b, c)"
    ]
   },
   {
@@ -588,7 +588,7 @@
     "\n",
     "a = (10, 6, 7)\n",
     "b = [2, 5, 3]\n",
-    "print (list(map(divid,a,b)))"
+    "print(list(map(divid,a,b)))"
    ]
   },
   {
@@ -633,7 +633,7 @@
     "    return tot\n",
     "\n",
     "w = [0, 1, 2, 3]\n",
-    "print (sum(w), PI)\n",
+    "print(sum(w), PI)\n",
     "\n"
    ]
   },
@@ -697,7 +697,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (ex1.PI)"
+    "print(ex1.PI)"
    ]
   },
   {
@@ -707,7 +707,7 @@
    "outputs": [],
    "source": [
     "ex1.PI = 3.141592653\n",
-    "print (ex1.PI)"
+    "print(ex1.PI)"
    ]
   },
   {
@@ -727,7 +727,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (ex1.sum([2, 3, 4]))"
+    "print(ex1.sum([2, 3, 4]))"
    ]
   },
   {
@@ -819,7 +819,7 @@
     "def test():\n",
     "    w = [0,1,2,3]\n",
     "    assert(sum(w) == 6)\n",
-    "    print ('test passed.')\n",
+    "    print('test passed.')\n",
     "\n",
     "if __name__ == '__main__':\n",
     "    test()\n"
@@ -1014,7 +1014,7 @@
     "        break\n",
     "    x = float(text)\n",
     "    y = math.log10(x)\n",
-    "    print (\"log10({0}) = {1}\".format(x, y))\n",
+    "    print(\"log10({0}) = {1}\".format(x, y))\n",
     "```\n",
     "\n",
     "这段代码接收命令行的输入，当输入为数字时，计算它的对数并输出，直到输入值为 `q` 为止。\n",
@@ -1036,7 +1036,7 @@
     "        break\n",
     "    x = float(text)\n",
     "    y = math.log10(x)\n",
-    "    print (\"log10({0}) = {1}\".format(x, y))\n"
+    "    print(\"log10({0}) = {1}\".format(x, y))\n"
    ]
   },
   {
@@ -1063,9 +1063,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = math.log10(x)\n",
-    "        print \"log10({0}) = {1}\".format(x, y)\n",
+    "        print(\"log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print (\"the value must be greater than 0\")\n",
+    "        print(\"the value must be greater than 0\")\n",
     "```"
    ]
   },
@@ -1093,9 +1093,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = math.log10(x)\n",
-    "        print (\"log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print (\"the value must be greater than 0\")\n"
+    "        print(\"the value must be greater than 0\")\n"
    ]
   },
   {
@@ -1119,9 +1119,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print \"log10({0}) = {1}\".format(x, y)\n",
+    "        print(\"log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print \"the value must be greater than 0\"\n",
+    "        print(\"the value must be greater than 0\")\n",
     "```\n",
     "\n",
     "假设我们将这里的 `y` 更改为 `1 / math.log10(x)`，此时输入 `1`："
@@ -1142,9 +1142,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print (\"the value must be greater than 0\")\n"
+    "        print(\"the value must be greater than 0\")\n"
    ]
   },
   {
@@ -1178,9 +1178,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"1 / log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"1 / log10({0}) = {1}\".format(x, y))\n",
     "    except Exception:\n",
-    "        print (\"invalid value\")\n"
+    "        print(\"invalid value\")\n"
    ]
   },
   {
@@ -1207,9 +1207,9 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"1 / log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"1 / log10({0}) = {1}\".format(x, y))\n",
     "    except (ValueError, ZeroDivisionError):\n",
-    "        print (\"invalid value\")\n"
+    "        print(\"invalid value\")\n"
    ]
   },
   {
@@ -1234,11 +1234,11 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"1 / log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"1 / log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print (\"the value must be greater than 0\")\n",
+    "        print(\"the value must be greater than 0\")\n",
     "    except ZeroDivisionError:\n",
-    "        print (\"the value must not be 1\")\n"
+    "        print(\"the value must not be 1\")\n"
    ]
   },
   {
@@ -1263,13 +1263,13 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"1 / log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"1 / log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError:\n",
-    "        print (\"the value must be greater than 0\")\n",
+    "        print(\"the value must be greater than 0\")\n",
     "    except ZeroDivisionError:\n",
-    "        print (\"the value must not be 1\")\n",
+    "        print(\"the value must not be 1\")\n",
     "    except Exception:\n",
-    "        print (\"unexpected error\")\n"
+    "        print(\"unexpected error\")\n"
    ]
   },
   {
@@ -1303,16 +1303,16 @@
     "            break\n",
     "        x = float(text)\n",
     "        y = 1 / math.log10(x)\n",
-    "        print (\"1 / log10({0}) = {1}\".format(x, y))\n",
+    "        print(\"1 / log10({0}) = {1}\".format(x, y))\n",
     "    except ValueError as exc:\n",
     "        if exc.message == \"math domain error\":\n",
-    "            print (\"the value must be greater than 0\")\n",
+    "            print(\"the value must be greater than 0\")\n",
     "        else:\n",
-    "            print (\"could not convert '%s' to float\" % text)\n",
+    "            print(\"could not convert '%s' to float\" % text)\n",
     "    except ZeroDivisionError:\n",
-    "        print (\"the value must not be 1\")\n",
+    "        print(\"the value must not be 1\")\n",
     "    except Exception as exc:\n",
-    "        print (\"unexpected error:\", exc.message)\n"
+    "        print(\"unexpected error:\", exc.message)\n"
    ]
   },
   {
@@ -1359,11 +1359,11 @@
    "outputs": [],
    "source": [
     "try:\n",
-    "    print (1)\n",
+    "    print(1)\n",
     "except:\n",
     "    pass\n",
     "else:\n",
-    "    print ('else was called.')"
+    "    print('else was called.')"
    ]
   },
   {
@@ -1380,11 +1380,11 @@
    "outputs": [],
    "source": [
     "try:\n",
-    "    print (1/0)\n",
+    "    print(1/0)\n",
     "except ZeroDivisionError:\n",
-    "    print ('divide by 0.')\n",
+    "    print('divide by 0.')\n",
     "else:\n",
-    "    print ('else was called.')"
+    "    print('else was called.')"
    ]
   },
   {
@@ -1405,9 +1405,9 @@
    "outputs": [],
    "source": [
     "try:\n",
-    "    print (1)\n",
+    "    print(1)\n",
     "finally:\n",
-    "    print ('finally was called.')"
+    "    print('finally was called.')"
    ]
   },
   {
@@ -1424,9 +1424,9 @@
    "outputs": [],
    "source": [
     "try:\n",
-    "    print (1 / 0)\n",
+    "    print(1 / 0)\n",
     "finally:\n",
-    "    print ('finally was called.')"
+    "    print('finally was called.')"
    ]
   },
   {
@@ -1443,11 +1443,11 @@
    "outputs": [],
    "source": [
     "try:\n",
-    "    print (1 / 0)\n",
+    "    print(1 / 0)\n",
     "except ZeroDivisionError:\n",
-    "    print ('divide by 0.')\n",
+    "    print('divide by 0.')\n",
     "finally:\n",
-    "    print ('finally was called.')\n"
+    "    print('finally was called.')\n"
    ]
   },
   {
@@ -1595,7 +1595,7 @@
    "outputs": [],
    "source": [
     "text = f.read()\n",
-    "print (text)"
+    "print(text)"
    ]
   },
   {
@@ -1613,7 +1613,7 @@
    "source": [
     "f = open('test.txt')\n",
     "lines = f.readlines()\n",
-    "print (lines)\n"
+    "print(lines)\n"
    ]
   },
   {
@@ -1647,7 +1647,7 @@
    "source": [
     "f = open('test.txt')\n",
     "for line in f:\n",
-    "    print (line)\n",
+    "    print(line)\n",
     "f.close()\n"
    ]
   },
@@ -1706,7 +1706,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print (open('myfile.txt').read())"
+    "print(open('myfile.txt').read())"
    ]
   },
   {
@@ -1725,7 +1725,7 @@
     "f = open('myfile.txt', 'w')\n",
     "f.write('another hello world!')\n",
     "f.close()\n",
-    "print (open('myfile.txt').read())\n"
+    "print(open('myfile.txt').read())\n"
    ]
   },
   {
@@ -1744,7 +1744,7 @@
     "f = open('myfile.txt', 'a')\n",
     "f.write('... and more')\n",
     "f.close()\n",
-    "print (open('myfile.txt').read())\n"
+    "print(open('myfile.txt').read())\n"
    ]
   },
   {
@@ -1765,7 +1765,7 @@
     "f = open('myfile.txt', 'w+')\n",
     "f.write('hello world!')\n",
     "f.seek(6)\n",
-    "print (f.read())\n",
+    "print(f.read())\n",
     "f.close()\n"
    ]
   },
@@ -1815,7 +1815,7 @@
     "f = open('newfile.txt','w')\n",
     "f.write('hello world')\n",
     "g = open('newfile.txt', 'r')\n",
-    "print (repr(g.read()))\n"
+    "print(repr(g.read()))\n"
    ]
   },
   {
@@ -1838,7 +1838,7 @@
     "    f.write('hello world: ' + str(i) + '\\n')\n",
     "\n",
     "g = open('newfile.txt', 'r')\n",
-    "print (g.read())\n",
+    "print(g.read())\n",
     "f.close()\n",
     "g.close()\n"
    ]
@@ -1886,7 +1886,7 @@
    "outputs": [],
    "source": [
     "g = open('newfile.txt', 'r')\n",
-    "print (g.read())\n",
+    "print(g.read())\n",
     "f.close()\n",
     "g.close()\n"
    ]
@@ -2045,7 +2045,7 @@
     "\n",
     "# 可以按行迭代数据\n",
     "for row in r:\n",
-    "    print (row)\n",
+    "    print(row)\n",
     "\n",
     "# 关闭文件\n",
     "fp.close()\n"
diff --git a/01.03 机器学习常用的包.ipynb b/01.03 机器学习常用的包.ipynb
index 9adc028..8f2da4b 100644
--- a/01.03 机器学习常用的包.ipynb
+++ b/01.03 机器学习常用的包.ipynb
@@ -1052,7 +1052,6 @@
    "source": [
     "# 生成 series\n",
     "s = pd.Series([1,3,5,np.nan,6,8])\n",
-    "\n",
     "print(s)"
    ]
   },
@@ -1064,9 +1063,7 @@
    "source": [
     "# 生成 dataframe \n",
     "dates = pd.date_range('20200101', periods=15)\n",
-    "\n",
     "df = pd.DataFrame(np.random.randn(15,4), index=dates, columns=list('ABCD'))\n",
-    "\n",
     "df"
    ]
   },