Difference between revisions of "Python:Control structures"
Jump to navigation
Jump to search
Line 16: | Line 16: | ||
block | block | ||
if somethinghappens: | if somethinghappens: | ||
− | break | + | break |
while expression: | while expression: | ||
block | block | ||
if somethinghappens: | if somethinghappens: | ||
− | + | continue | |
</syntaxhighlight> | </syntaxhighlight> | ||
+ | ;<code>break</code> | ||
+ | :Stop looping immediately. Jump to the next statement after the loop. | ||
+ | ;<code>continue</code> | ||
+ | :Stop the current iteration immediately and jump the the top of the loop, do the next iteration. | ||
;<code>pass</code> | ;<code>pass</code> | ||
:No operation, use e.g. to avoid negative tests | :No operation, use e.g. to avoid negative tests |
Revision as of 13:16, 13 January 2021
Most flow control is standard. Indentation defines the code block to execute. You must be strict, all indents must be the same in a block, a mix of spaces and tabs is not allowed (unless each line uses the same mix).
You can define you own Python:Functions too.
if expression:
block
elif expression:
block
else:
otherblock
for var1 in itterable: # keys if itterable is a dict
block
if somethinghappens:
break
while expression:
block
if somethinghappens:
continue
break
- Stop looping immediately. Jump to the next statement after the loop.
continue
- Stop the current iteration immediately and jump the the top of the loop, do the next iteration.
pass
- No operation, use e.g. to avoid negative tests
var1 = ( x if <condition> else y )
- No operation, use e.g. to avoid negative tests
Exception handling
To catch exceptions:
try:
blockthatmaythowexception
except <exception>:
blockifexceptionisthrown
else:
blockifNOexceptionisthrown
Specifying an exception is optional but highly recommended. The exceptiontypes can be found in the python docs
- except NameError
- The variable does not exist
- except KeyError
- The key does not exist in the dict
- except IndexError
- The index does not exist in the list