CP215 Application Design

Transcription

1 CP215 Application Design

2 New ATLAS humanoid robot: Tech News!

3 Tech News! New ATLAS humanoid robot: Spotify moving data to Google Cloud

4 Hacker's Tip of the Day Obey the Rule of Prototyping Almost all programs must be rewritten

5 Hacker's Tip of the Day Obey the Rule of Prototyping Almost all programs must be rewritten Writing the program is part of the process of understanding the program

6 Hacker's Tip of the Day Obey the Rule of Prototyping Almost all programs must be rewritten Writing the program is part of the process of understanding the program Develop a prototype and expect to throw it away

7 Sparse Matrices and Vectors Sparse Matrix [7 2 5 ] Sparse Vector

8 Sparse Vector Class? [7 2 5 ] Sparse Vector

9 SparseVector Class class SparseVector: def init (self): self.values = {} def getvalue(self, index): return self.values[index] def addvalue(self, index, value): self.values[index] = value

10 SparseVector Class if name == main : sv = SparseVector() sv.addvalue(55, 12) sv.addvalue(7, 1) print sv.getvalue(55) print sv.getvalue(7)

11 SparseVector Class class SparseVector: def init (self): self.values = {} def getitem (self, index): return self.values[index] def setitem (self, index, value): self.values[index] = value

12 SparseVector Class if name == main : sv = SparseVector() sv[55] = 12 sv[7] = 1 print sv[55] print sv[7]

13 class SparseVector: def init (self): self.values = {} def getitem (self, index): return self.values[index] def setitem (self, index, value): self.values[index] = value def len (self): return len(self.values) def str (self): result = '' for key, value in self.values.items(): result += key +, + value + \n return result

14 class SparseVector:... def getslice (self, index1, index2):???

15 class SparseVector:... def getslice (self, index1, index2): new_sv = SparseVector() for key, value in self.values.items(): if key >= index1 and key < index2: new_sv[key] = value return new_sv

16 Other Special Methods del eq call iter contains add sub Called when object is being destroyed Called to compare two objects Called when object is called: obj() Called to create an iterator over object Called for membership tests Called to add two objects together Called to subtract one object from another

17 Automatic Building with make Python is easy to run Interpreted language, no compilation!

18 Automatic Building with make Python is easy to run Interpreted language, no compilation! Certain pieces of a larger project depend on others A wave visualization program might depend on your Wave wrapper class

19 Automatic Building with make Makefile Describes dependencies between parts of a project Automates compilation when small changes are made to just some of the files

20 Automatic Building with make Makefile Describes dependencies between parts of a project Automates compilation when small changes are made to just some of the files Can automate other things as well: Installation of program Running project tests Creating/viewing program documentation

21 Example Makefile Name of the make operation. Defined by you. A list of source code files. If any of these change, the target must be recompiled. target: source_files command Run this command when the target needs to be remade.

22 Example Makefile SITE_PACKAGES=/usr/local/lib/python2.7/site-packages/ program: python myprogram.py test: python test_myprogram.py install: cp myprogram.py $(SITE_PACKAGES)

23 SITE_PACKAGES=/usr/local/lib/python2.7/site-packages/ PROGRAM = myprogram.py MODULE = myprogram TEST_PROGRAM = test_myprogram.py DOCUMENTATION_PROGRAM = pydoc -w program: python $(PROGRAM) test: python $(TEST_PROGRAM) install: cp $(PROGRAM) $(SITE_PACKAGES) document: $(DOCUMENTATION_PROGRAM) $(MODULE)

24 Full Sparse Vector Project SparseVector Class Documentation for functions Use of special functions SparseVector test file Test for correctness Test for speed/efficiency Makefile Run tests easily and automatically

25 Break!