tungwaiyip.info

home

about me

links

Blog

< June 2012 >
SuMoTuWeThFrSa
      1 2
3 4 5 6 7 8 9
10111213141516
17181920212223
24252627282930

past articles »

Click for San Francisco, California Forecast

San Francisco, USA

 

Python Whitespace Misconception

Whitespace is significant in Python. This uncommon syntax rule is one of the refrain of many non-Python programmers about Python. Given most computer languages since Fortran has adopted free layout syntax, this feel like an objectionable design.

Now that I think of it, I find this mostly a problem of wrong framing. The term "whitespace" has already embedded the meaning of unimportant filler. In this sense "significant whitespace" sounds like a problem. Actually the right way to describe it is that Python uses indentation to determine the block structure. Rather than feeling wrong, this is lot more likely to evoke an "aha" reaction from non-Python programmers. Of course it makes a lot sense for the indentation to follow the block structure. I can hardly find any legitimate case for those two to differ.

Austere programmers may notice that there are two way to indicate block structure in main stream languages, by using language construct like "begin" and "end" and by laying out the code using indentation. Whenever there are two ways to do express one thing there will be problem of inconsistency. This extra degree of freedom can get you into trouble sometimes. One of the most nasty class of programming bug is dangling else. It is the case in free layout language when the apparent block structure is different from the actual block structure. Dangling else is not possible in Python. It is because the block structure is determined by the indentation.

2012.06.08 [] - comments

 

 

blog comments powered by Disqus

past articles »

 

BBC News

 

Coronavirus: Trump extends US guidelines beyond Easter (30 Mar 2020)

 

Trump says Harry and Meghan must pay for security (29 Mar 2020)

 

Coronavirus: Mercedes F1 to make breathing aid (29 Mar 2020)

 

Fears of domestic workers who can't stay home (29 Mar 2020)

 

North Korea hails 'super large' launcher test as virus timing condemned (30 Mar 2020)

 

UK government cracks down on virus fake news (29 Mar 2020)

 

London's roads in the coronavirus pandemic (29 Mar 2020)

 

Alan Merrill: I Love Rock 'N' Roll songwriter dies of coronavirus (30 Mar 2020)

 

Johnson hails return of 20,000 ex-NHS staff (30 Mar 2020)

 

Message from president who led Ebola battle (30 Mar 2020)

more »

 

SF Gate

 

Facebook scrambles to keep up with soaring use as employees work from home (29 Mar 2020)

 

Coronavirus has opened corporate email floodgates (29 Mar 2020)

 

Big Tech could emerge from coronavirus crisis stronger than ever (29 Mar 2020)

 

Stocks drop but hold on to weekly gains (28 Mar 2020)

 

Ship traffic, March 29 (27 Mar 2020)

 

Ship traffic, March 30 (27 Mar 2020)

more »


Site feed Updated: 2020-Mar-30 03:00