X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=slides%2Fcaesar-encipher.html;h=4afd78dad4f3367c5107a99d0f40ff8f1e0aa037;hb=7203ac94911556e2b4bf4caab6f5285445faed3b;hp=3bc519c9b59c27f05785cced5ea703da9f715d8a;hpb=ee8bb0b7953e32c988f4faa72c0eb4c6cd6e4ea8;p=cipher-training.git diff --git a/slides/caesar-encipher.html b/slides/caesar-encipher.html index 3bc519c..4afd78d 100644 --- a/slides/caesar-encipher.html +++ b/slides/caesar-encipher.html @@ -37,6 +37,11 @@ text-shadow: 0 0 20px #333; padding: 2px 5px; } + .indexlink { + position: absolute; + bottom: 1em; + left: 1em; + } @@ -50,6 +55,12 @@ Letter-by-letter enciphering --- +layout: true + +.indexlink[[Index](index.html)] + +--- + # Enciphering and deciphering ## Arithmetic on letters @@ -71,6 +82,34 @@ chr() --- +# Using the tools + +Before doing anything, create a new branch in Git + +* This will keep your changes isolated + +Experiment in IPython (ephemeral, for us) + +Once you've got something working, copy the code into a `.py` file (permanent and reusable) + +```python +from imp import reload + +import test +reload(test) +from test import * +``` + +Re-evaluate the second cell to reload the file into the IPython notebook + +When you've made progress, make a Git commit + +* Commit early and often! + +When you've finished, change back to `master` branch and `merge` the development branch + +--- + # The [string module](http://docs.python.org/3.3/library/string.html) is your friend ```python @@ -84,6 +123,7 @@ string.punctuation ``` --- + # DRY and YAGNI Is your code DRY? @@ -120,7 +160,7 @@ if __name__ == "__main__": --- -# Doing all the letters +# Doing the whole message ## Test-first developement @@ -131,7 +171,7 @@ if __name__ == "__main__": --- -# Doing all the letters +# Doing the whole message ## Abysmal @@ -141,9 +181,11 @@ for i in range(len(plaintext)): ciphertext += caesar_encipher_letter(plaintext[i], key) ``` +Try it in IPython + --- -# Doing all the letters +# Doing the whole message ## Bad @@ -157,7 +199,7 @@ for p in plaintext: --- -# Doing all the letters +# Doing the whole message ## Good (but unPythonic) @@ -167,7 +209,7 @@ ciphertext = map(lambda p: caesar_encipher_letter(p, key), plaintext) --- -# Doing all the letters +# Doing the whole message ## Best