From 8e9944fd0e89f0fc79eccefa3c055070b8d126e6 Mon Sep 17 00:00:00 2001
From: Martijn Vermaat <martijn@vermaat.name>
Date: Tue, 23 Jul 2013 16:57:52 +0200
Subject: [PATCH] String formatting and modules
---
python-intro/fibonacci.py | 10 +
python-intro/python-intro.ipynb | 325 +++++++++++++++++++++++++++++---
2 files changed, 311 insertions(+), 24 deletions(-)
create mode 100644 python-intro/fibonacci.py
diff --git a/python-intro/fibonacci.py b/python-intro/fibonacci.py
new file mode 100644
index 0000000..75da24c
--- /dev/null
+++ b/python-intro/fibonacci.py
@@ -0,0 +1,10 @@
+def fib(n):
+ if n == 0:
+ return 0
+ if n == 1:
+ return 1
+ return fib(n - 1) + fib(n - 2)
+
+if __name__ == '__main__':
+ for n in range(5, 10):
+ print 'fib({0}) = {1}'.format(n, fib(n))
diff --git a/python-intro/python-intro.ipynb b/python-intro/python-intro.ipynb
index 5f2de08..3715a7a 100644
--- a/python-intro/python-intro.ipynb
+++ b/python-intro/python-intro.ipynb
@@ -198,7 +198,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
- "* Statement by statement directly in the interpreter"
+ "* Statement by statement directly in the interpreter."
]
},
{
@@ -213,7 +213,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
- "* By editing in a file running the code afterwards"
+ "* By editing in a file and running the code afterwards."
]
},
{
@@ -1065,7 +1065,7 @@
}
},
"source": [
- "Mutable ordered sequences of values."
+ "Mutable sequences of values."
]
},
{
@@ -1144,7 +1144,7 @@
}
},
"source": [
- "Immutable ordered sequences of values."
+ "Immutable sequences of values."
]
},
{
@@ -1206,7 +1206,7 @@
"level": 2,
"metadata": {},
"source": [
- "Strings"
+ "Strings (1/2)"
]
},
{
@@ -1217,14 +1217,14 @@
}
},
"source": [
- "The special formatting operator `%` replaces conversion specifications by values."
+ "Immutable sequences of characters."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
- "'%s times %i equals %.3f' % ('pi', 2, 6.283185307179586)"
+ "'a string can be written in single quotes'"
],
"language": "python",
"metadata": {},
@@ -1232,13 +1232,13 @@
{
"metadata": {},
"output_type": "pyout",
- "prompt_number": 30,
+ "prompt_number": 108,
"text": [
- "'pi times 2 equals 6.283'"
+ "'a string can be written in single quotes'"
]
}
],
- "prompt_number": 30
+ "prompt_number": 108
},
{
"cell_type": "markdown",
@@ -1289,13 +1289,101 @@
],
"prompt_number": 32
},
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {
+ "slideshow": {
+ "slide_type": "subslide"
+ }
+ },
+ "source": [
+ "Sequence types"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Strings (2/2)"
+ ]
+ },
{
"cell_type": "markdown",
"metadata": {},
"source": [
- "Strings are immutable."
+ "A common operation is formatting strings using argument substitutions."
]
},
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "'{} times {} equals {:.2f}'.format('pi', 2, 6.283185307179586)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "metadata": {},
+ "output_type": "pyout",
+ "prompt_number": 117,
+ "text": [
+ "'pi times 2 equals 6.28'"
+ ]
+ }
+ ],
+ "prompt_number": 117
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "Accessing arguments by position or name is more readable."
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "'{1} times {0} equals {2:.2f}'.format('pi', 2, 6.283185307179586)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "metadata": {},
+ "output_type": "pyout",
+ "prompt_number": 116,
+ "text": [
+ "'2 times pi equals 6.28'"
+ ]
+ }
+ ],
+ "prompt_number": 116
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "'{number} times {amount} equals {result:.2f}'.format(number='pi', amount=2,\n",
+ " result=6.283185307179586)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "metadata": {},
+ "output_type": "pyout",
+ "prompt_number": 118,
+ "text": [
+ "'pi times 2 equals 6.28'"
+ ]
+ }
+ ],
+ "prompt_number": 118
+ },
{
"cell_type": "heading",
"level": 1,
@@ -3609,34 +3697,205 @@
}
},
"source": [
- "Exceptions"
+ "Modules"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Non-interactive programming"
]
},
{
"cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "* Real work needs to be saved to files.\n",
+ "* Larger programs need modular development.\n",
+ "* A `.py` file (with Python code) is called a module.\n",
+ "\n",
+ "Example:"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "cat fibonacci.py"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "def fib(n):\r\n",
+ " if n == 0:\r\n",
+ " return 0\r\n",
+ " if n == 1:\r\n",
+ " return 1\r\n",
+ " return fib(n - 1) + fib(n - 2)\r\n",
+ "\r\n",
+ "if __name__ == '__main__':\r\n",
+ " for n in range(5, 10):\r\n",
+ " print 'fib({0}) = {1}'.format(n, fib(n))\r\n"
+ ]
+ }
+ ],
+ "prompt_number": 130
+ },
+ {
+ "cell_type": "heading",
+ "level": 1,
"metadata": {
"slideshow": {
- "slide_type": "-"
+ "slide_type": "subslide"
}
},
"source": [
- "Todo.\n",
- "\n",
- "* Handling exceptions with ``try...except``."
+ "Modules"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Using code from a module"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "You can import a module into your code."
]
},
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import fibonacci\n",
+ "fibonacci.fib(7)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "metadata": {},
+ "output_type": "pyout",
+ "prompt_number": 122,
+ "text": [
+ "13"
+ ]
+ }
+ ],
+ "prompt_number": 122
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "Or you can run the module directly."
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "%%sh\n",
+ "python fibonacci.py"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "fib(5) = 5\n",
+ "fib(6) = 8\n",
+ "fib(7) = 13\n",
+ "fib(8) = 21\n",
+ "fib(9) = 34\n"
+ ]
+ }
+ ],
+ "prompt_number": 131
+ },
{
"cell_type": "heading",
"level": 1,
"metadata": {
"slideshow": {
- "slide_type": "slide"
+ "slide_type": "subslide"
}
},
"source": [
"Modules"
]
},
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Working with files in IPython"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "You can run a module directly in IPython."
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "%run fibonacci.py"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "fib(5) = 5\n",
+ "fib(6) = 8\n",
+ "fib(7) = 13\n",
+ "fib(8) = 21\n",
+ "fib(9) = 34\n"
+ ]
+ }
+ ],
+ "prompt_number": 135
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "fib(12)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "metadata": {},
+ "output_type": "pyout",
+ "prompt_number": 136,
+ "text": [
+ "144"
+ ]
+ }
+ ],
+ "prompt_number": 136
+ },
{
"cell_type": "markdown",
"metadata": {
@@ -3645,33 +3904,50 @@
}
},
"source": [
- "Todo.\n",
- "\n",
- "- Edit code in a file and running it with ``%ed filename.py``.\n",
- "- Running it with ``python filename.py``."
+ "You can edit and run a file with `%edit`."
]
},
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "%edit fibonacci.py"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [],
+ "prompt_number": 134
+ },
{
"cell_type": "heading",
"level": 1,
"metadata": {
"slideshow": {
- "slide_type": "skip"
+ "slide_type": "slide"
}
},
"source": [
- "Extras"
+ "Todo"
]
},
{
"cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "* Handling exceptions with `try ... except`.\n",
+ "* Interpreting a stack trace."
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 1,
"metadata": {
"slideshow": {
"slide_type": "skip"
}
},
"source": [
- "Some style overrides and a table of contents."
+ "Extras"
]
},
{
@@ -3682,6 +3958,7 @@
}
},
"source": [
+ "Some style overrides.\n",
"<style type=\"text/css\">\n",
".reveal {\n",
" overflow-y: hidden;\n",
--
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