Appion

Python Coding Standards » History » Revision 2

Revision 1 (Neil Voss, 03/19/2010 02:11 PM) → Revision 2/7 (Neil Voss, 03/19/2010 02:19 PM)

h1. Python Coding Standards 

 This document is a list of python coding standards. To add a new standard copy the template below and modify it. 

 see also http://emg.nysbc.org/wiki/index.php/Appionscripts_formatting_rules 

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 h2. +Name of Coding Standard+ 

 h3. Definition 

 What is the coding standard 

 h3. Justification 

 Why is the coding standard important 

 h3. Example 

 GOOD:<pre> 
 this is a good example code 
 </pre> 

 BAD:<pre> 
 this is a bad example code 
 </pre> 

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 h1. Python Coding Standards for AMI 

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 h2. +Use tabs instead of spaces+ 

 h3. Definition 

 Use tabs instead of spaces for inline code 

 h3. Justification 

 It is important to be consistent. People like different sizes of columns, so like 8 spaces, others 4, 3, or 2. With tabs each individual can customize their viewer. 

 h3. Example 

 GOOD:<pre> 
 if True: 
 <tab>while True: 
 <tab><tab>print "tab" 
 <tab>break 
 </pre> 

 BAD:<pre> 
 if True: 
    while True: 
         print "tab" 
    break 
 </pre> 

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 h2. +Checking beginning or ending of strings+ 

 h3. Definition 

 Use ''.startswith() and ''.endswith() instead of string slicing to check for prefixes or suffixes. 

 h3. Justification 

 startswith() and endswith() are cleaner and less error prone. 

 h3. Example 

 GOOD:<pre> 
 if foo.startswith('bar'):  
 </pre> 

 BAD:<pre> 
 if foo[:3] == 'bar': 
 </pre> 

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 h2. +Never use @from module import *@+ 

 h3. Definition 

 Never use @from module import *@, use @import module@ instead 

 h3. Justification 

 It is hard to track where functions come from when @import *@ is used 

 h3. Example 

 GOOD:<pre> 
 import numpy 
 a = numpy.ones((3,3)) 
 </pre> 

 BAD:<pre> 
 from numpy import * 
 a = ones((3,3)) 
 </pre> 

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 h2. +Appion image data naming conventions+ 

 h3. Definition 

 # never use 'image' or 'img' 
 # use 'imgdict' for image dictionaries 
 # use 'imgarray' for image numarrays 
 # use 'imgname' for image filenames 
 # use 'imgtree' for the main list of image dictionaries 
 # use 'imglist' for a list of image data  

 h3. Justification 

 If you are consistent with your names people can read your code. 

 h3. Example 

 GOOD:<pre> 
 for imgdict in imgtree: 
	 imgarray = imgdict['image'] 
	 imgname = imgdict['filename'] 
 </pre> 

 BAD:<pre> 
 for image in imgs: 
	 array = image['image'] 
	 name = image['filename'] 
 </pre>