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+--- Thread: Magic method __str__ (/thread-14812.html)
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RE: Magic method __str__ - dan789 - Dec-19-2018
@nilamo no, I don´t want to copy a list inside a function, all what I need is this function should work for changes in a list. For example, after __init__ (which creates a list self.tab) I want __str__() to create a string from this list. Using the code by @buran few posts above it works, but I need to call this method also later, after some changes in this self.tab happen. And these are specifically "." changed to a set. After this, method __str__() create a string consisting of numbers and sets, but I still want to put "." instead of sets here.
RE: Magic method __str__ - dan789 - Dec-22-2018
UP....
RE: Magic method __str__ - ichabod801 - Dec-22-2018
def __str__(self):
lines = []
for sub_list in self.tab:
lines.append(' '.join([str(item) for item in sub_list if not isinstance(item, set) else '.']))
return '\n'.join(lines)
RE: Magic method __str__ - dan789 - Dec-22-2018
This raises me an invalid syntax error and not sure what is wrong there.. :/
RE: Magic method __str__ - ichabod801 - Dec-22-2018
Sorry, that should be:
def __str__(self):
lines = []
for sub_list in self.tab:
lines.append(' '.join([str(item) if not isinstance(item, set) else '.' for item in sub_list]))
return '\n'.join(lines)
RE: Magic method __str__ - dan789 - Dec-23-2018
@ichabod801 thanks, this seems working, the only thing missing (I forgot to mentioned that, but I guess it´s just an addition into this generator notation) - if length of set is 1, it should put that one item (number) into that string, instead of "."
Is it possible to add "elif" statement there?
RE: Magic method __str__ - ichabod801 - Dec-23-2018
No, you can't put an elif in a ternary statement. You would have to break that list comprehension out into a loop with a full conditional statement.