Rework the introduction on numpy

- expand section on indexing and slicing in Chapter 1 on arrays
- add section on dimensionality and shapes of arrays
- streamline text in Chapter 1
- include thumbnails in links to scientific libraries
- add explanation on slicing to core Python introduction
  and adjust the list example
- streamline some text and titles in Chapter 0

00_python_in_a_nutshell/02_content_logic.ipynb

@@ -36,7 +36,7 @@
     "\n",
     "The syntax to create a `list` are brackets, `[` and `]`, another example of delimiters, listing the individual **elements** of the `list` in between them, separated by commas.\n",
     "\n",
-    "For example, the next code snippet creates a `list` named `numbers` with the numbers `1`, `2`, `3`, and `4` in it."
+    "For example, the next code snippet creates a `list` named `numbers` with the numbers `1`, `2`, `3`, `4`, and `5` in it."
    ]
   },
   {
@@ -47,7 +47,7 @@
     {
      "data": {
       "text/plain": [
-       "[1, 2, 3, 4]"
+       "[1, 2, 3, 4, 5]"
       ]
      },
      "execution_count": 1,
@@ -56,7 +56,7 @@
     }
    ],
    "source": [
-    "numbers = [1, 2, 3, 4]\n",
+    "numbers = [1, 2, 3, 4, 5]\n",
     "\n",
     "numbers"
    ]
@@ -65,7 +65,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Whenever we use any kind of delimiter, we may break the lines in between them as we wish and add other so-called **whitespace** characters like spaces to format the way the code looks like. So, the following two code cells do *exactly* the same as the previous one, even the `,` after the `4` in the second cell is ignored."
+    "Whenever we use any kind of delimiter, we may break the lines in between them as we wish and add other so-called **whitespace** characters like spaces to format the way the code looks like. So, the following two code cells do *exactly* the same as the previous one, even the `,` after the `5` in the second cell is ignored."
    ]
   },
   {
@@ -76,7 +76,7 @@
     {
      "data": {
       "text/plain": [
-       "[1, 2, 3, 4]"
+       "[1, 2, 3, 4, 5]"
       ]
      },
      "execution_count": 2,
@@ -86,7 +86,7 @@
    ],
    "source": [
     "numbers = [\n",
-    "    1, 2, 3, 4\n",
+    "    1, 2, 3, 4, 5\n",
     "]\n",
     "\n",
     "numbers"
@@ -100,7 +100,7 @@
     {
      "data": {
       "text/plain": [
-       "[1, 2, 3, 4]"
+       "[1, 2, 3, 4, 5]"
       ]
      },
      "execution_count": 3,
@@ -114,6 +114,7 @@
     "    2,\n",
     "    3,\n",
     "    4,\n",
+    "    5,\n",
     "]\n",
     "\n",
     "numbers"
@@ -135,6 +136,13 @@
     "num"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Indexing & Slicing"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -183,7 +191,7 @@
     {
      "data": {
       "text/plain": [
-       "4"
+       "5"
       ]
      },
      "execution_count": 5,
@@ -210,7 +218,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "numbers[0] = 4"
+    "numbers[0] = 5"
    ]
   },
   {
@@ -219,7 +227,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "numbers[3] = 1"
+    "numbers[4] = 1"
    ]
   },
   {
@@ -230,7 +238,7 @@
     {
      "data": {
       "text/plain": [
-       "[4, 2, 3, 1]"
+       "[5, 2, 3, 4, 1]"
       ]
      },
      "execution_count": 8,
@@ -255,7 +263,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "numbers[0], numbers[3] = numbers[3], numbers[0]"
+    "numbers[0], numbers[4] = numbers[4], numbers[0]"
    ]
   },
   {
@@ -266,7 +274,7 @@
     {
      "data": {
       "text/plain": [
-       "[1, 2, 3, 4]"
+       "[1, 2, 3, 4, 5]"
       ]
      },
      "execution_count": 10,
@@ -278,6 +286,174 @@
     "numbers"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "As a generalization, we may also **slice** out some elements in the `list`. That is done with the `[...]` notation as well. Yet, instead of a single integer index, we now provide a *start* and a *stop* index separated by a `:`. While the element corresponding to the *start* index is included, this is not the case for *stop*.\n",
+    "\n",
+    "For example, to slice out the middle three elements, we write the following."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[2, 3, 4]"
+      ]
+     },
+     "execution_count": 11,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[1:4]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "We may combine positive and negative indexes.\n",
+    "\n",
+    "So, the following yields the same result."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[2, 3, 4]"
+      ]
+     },
+     "execution_count": 12,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[1:-1]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "While ommitting the *start* index makes a slice begin at the first element, ..."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[1, 2, 3, 4]"
+      ]
+     },
+     "execution_count": 13,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[:-1]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "... leaving out the *stop* index makes a slice go to the last element."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[2, 3, 4, 5]"
+      ]
+     },
+     "execution_count": 14,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[1:]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Providing a third integer as the *step* value after another `:` makes a slice skip some elements.\n",
+    "\n",
+    "For example, `[1:-1:2]` means \"go from the second element (including) to the last element (excluding) and take every second element\" ..."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[2, 4]"
+      ]
+     },
+     "execution_count": 15,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[1:-1:2]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "... while `[::2]` simply downsamples the `list` by taking every other element."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[1, 3, 5]"
+      ]
+     },
+     "execution_count": 16,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "numbers[::2]"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -333,21 +509,21 @@
     "\n",
     "Many beginners struggle with the term \"loop.\" To visualize the looping behavior of this code, we use the online tool [PythonTutor <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_py.png\">](http://pythontutor.com/visualize.html#code=numbers%20%3D%20%5B1,%202,%203,%204%5D%0A%0Atotal%20%3D%200%0A%0Afor%20number%20in%20numbers%3A%0A%20%20%20%20total%20%3D%20total%20%2B%20number%0A%0Atotal&cumulative=false&curInstr=0&heapPrimitives=nevernest&mode=display&origin=opt-frontend.js&py=3&rawInputLstJSON=%5B%5D&textReferences=false). That tool is helpful for two reasons:\n",
     "1. It allows us to execute code in \"slow motion\" (i.e., by clicking the \"next\" button on the left side, only the next atomic step of the code snippet is executed).\n",
-    "2. It shows what happens inside the computer's memory on the right-hand side (cf., the \"*Thinking like a Computer*\" section further below)."
+    "2. It shows what happens inside the computer's memory on the right-hand side."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 17,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "10"
+       "15"
       ]
      },
-     "execution_count": 11,
+     "execution_count": 17,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -370,16 +546,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 18,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "10"
+       "15"
       ]
      },
-     "execution_count": 12,
+     "execution_count": 18,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -395,16 +571,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 19,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "10"
+       "15"
       ]
      },
-     "execution_count": 13,
+     "execution_count": 19,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -434,7 +610,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 20,
    "metadata": {},
    "outputs": [
     {
@@ -443,7 +619,7 @@
        "1"
       ]
      },
-     "execution_count": 14,
+     "execution_count": 20,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -454,7 +630,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 21,
    "metadata": {},
    "outputs": [
     {
@@ -463,7 +639,7 @@
        "0"
       ]
      },
-     "execution_count": 15,
+     "execution_count": 21,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -481,7 +657,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 22,
    "metadata": {},
    "outputs": [
     {
@@ -490,7 +666,7 @@
        "False"
       ]
      },
-     "execution_count": 16,
+     "execution_count": 22,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -501,7 +677,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 23,
    "metadata": {},
    "outputs": [
     {
@@ -510,7 +686,7 @@
        "True"
       ]
      },
-     "execution_count": 17,
+     "execution_count": 23,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -544,7 +720,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 24,
    "metadata": {},
    "outputs": [
     {
@@ -553,7 +729,7 @@
        "6"
       ]
      },
-     "execution_count": 18,
+     "execution_count": 24,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -579,21 +755,21 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "`if` statements may have more than one header line: For example, the code in the `else`-clause's body is only executed if the condition in the `if`-clause is `False`. In the code cell below, we calculate the sum of all even numbers and subtract the sum of all odd numbers. The result is `(2 + 4) - (1 + 3)`, or `-1 + 2 - 3 + 4` resembling the order of the numbers in the `for`-loop."
+    "`if` statements may have more than one header line: For example, the code in the `else`-clause's body is only executed if the condition in the `if`-clause is `False`. In the code cell below, we calculate the sum of all even numbers and subtract the sum of all odd numbers. The result is `(2 + 4) - (1 + 3 + 5)`, or `-1 + 2 - 3 + 4 - 5` resembling the order of the numbers in the `for`-loop."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 25,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "2"
+       "-3"
       ]
      },
-     "execution_count": 19,
+     "execution_count": 25,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -621,7 +797,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 26,
    "metadata": {},
    "outputs": [
     {
@@ -658,7 +834,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 27,
    "metadata": {},
    "outputs": [
     {
@@ -706,7 +882,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 28,
    "metadata": {},
    "outputs": [
     {
@@ -747,7 +923,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 29,
    "metadata": {},
    "outputs": [
     {
@@ -788,7 +964,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 30,
    "metadata": {},
    "outputs": [
     {

00_python_in_a_nutshell/05_content_functions.ipynb

@@ -29,7 +29,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## User-defined Functions"
+    "## Defining Functions"
    ]
   },
   {
@@ -151,7 +151,7 @@
      "traceback": [
       "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
       "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
-      "\u001b[0;32m/tmp/user/1000/ipykernel_305654/1049141082.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mresult\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/tmp/user/1000/ipykernel_707190/1049141082.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mresult\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
       "\u001b[0;31mNameError\u001b[0m: name 'result' is not defined"
      ]
     }
@@ -393,7 +393,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Extending Core Python with the Standard Library"
+    "## The Standard Library"
    ]
   },
   {
@@ -429,7 +429,7 @@
     {
      "data": {
       "text/plain": [
-       "0.44374384200665107"
+       "0.7021021034327006"
       ]
      },
      "execution_count": 16,