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

 

Brexit: Backstop indispensable, Macron tells Johnson (22 Aug 2019)

 

Amazon fires: Bolsonaro says Brazil cannot fight them (22 Aug 2019)

 

South Korea and Japan's feud explained (22 Aug 2019)

 

Poland lightning strike kills four, injures 100, in Tatra mountains storm (22 Aug 2019)

 

Indonesia cuts off internet to Papua following protests (22 Aug 2019)

 

Execution set for US killer who preyed on gay men (22 Aug 2019)

 

Qandeel Baloch: Parents fail to free brothers accused of killing sister (22 Aug 2019)

 

Giraffes given greater protection from unregulated trade as numbers fall (22 Aug 2019)

 

Huge beehive discovered inside ceiling (22 Aug 2019)

 

Huawei's Meng Wanzhou not a bargaining chip, says Pompeo (22 Aug 2019)

more »

 

SF Gate

 

Ship traffic (22 Aug 2019)

 

Spider-Man fights evil on his own after Sony-Disney split (21 Aug 2019)

 

Walmart sues Tesla over fires from solar panels atop stores (21 Aug 2019)

 

Reining in Big Tech with more regulation (21 Aug 2019)

 

Ship traffic, August 22 (21 Aug 2019)

 

Companies starting to worry about effects of tariffs on consumers (20 Aug 2019)

more »


Site feed Updated: 2019-Aug-22 15:00