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Mostly Linux & Python syntax notes and hyperlinks.
Wednesday, December 16, 2015
Using Workflowy to dissect a task into do-able bits
Tuesday, December 8, 2015
python: Nonintuitive ELSE after FOR or WHILE
When I first saw an else clause after a for loop, I concluded that those were the steps to run if the condition inside the loop was never true-- that is, either you enter the loop or you do its else.
Wrong: Those are the steps to run if you exit the loop without a break statement.
A better label would be NO_BREAK, but I understand not wanting to add keywords to the language.
Test: Are the else steps executed when the loop is never entered?
output
Wrong: Those are the steps to run if you exit the loop without a break statement.
A better label would be NO_BREAK, but I understand not wanting to add keywords to the language.
Test: Are the else steps executed when the loop is never entered?
for thing in ['abc','','tobreak','ok']:
print "\nvertical [%s]" % thing
for c in thing:
print c
if c=='r':
break
else:
print "No r in [%s]" % thing
else:
print "\nthat's all"
output
vertical [abc]
a
b
c
No r in [abc]
vertical []
No r in []
vertical [tobreak]
t
o
b
r
vertical [ok]
o
k
No r in [ok]
that's all
Process finished with exit code 0
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