python print class text passed to a variable

Question

I want to write to a text file the function text as it is passed to a variable:

myvariable = myClass(arg1, arg2, arg3, arg4, arg_n)

f = open("mytextfile.txt", "w")
f.write("here is my paremeters:"+ str(myvariable))
f.close()

in my printout text file, I get:

"here is my parameters:<somefunction.myClass instance at 0x7d54a5101b48>"

the desired output will be:

"here is my parameters: myClass(arg1, arg2, arg3, arg4, arg_n)"

I should use the myvariable because the arguments change from time to time, so I can't hardcode the function text as it is.

how did you get that and not the result of run de function? is it your function defined? — Tzomas, Mar 15 '17 at 09:31
@Tzomas sorry you r right, it is a class, not a function. anyway, it doens't affect my question... — jacky, Mar 15 '17 at 09:34
Possible duplicate of [How do I change the string representation of a Python class?](http://stackoverflow.com/questions/4912852/how-do-i-change-the-string-representation-of-a-python-class) — OneCricketeer, Mar 15 '17 at 09:36
what is myClass, does it has any function or constructor or anything? — Hackaholic, Mar 15 '17 at 09:38
@cricket_007 here is the exact file I am using https://github.com/JustGlowing/minisom/blob/master/minisom.py class MiniSom — jacky, Mar 15 '17 at 09:43
@Hackaholic here is my class that i use https://github.com/JustGlowing/minisom/blob/master/minisom.py — jacky, Mar 15 '17 at 09:43
Then extend that class and/or implement your own `str()` implementation on it — OneCricketeer, Mar 15 '17 at 09:46
@cricket_007 could you please suggest an answer with your solution? thanks in advance. — jacky, Mar 15 '17 at 09:49

OneCricketeer · Answer 1 · 2017-03-15T10:09:31.587

Since you commented with a third-party library and this isn't your own class...

Not pretty, but it works.

def string_it(c):
    return """myClass({}, {}, {}, {}, {})""".format(
        c.arg1, c.arg2, c.arg3, c.arg4, c.argN
    )

f.write("here are my parameters: {}\n".format(string_it(myvariable)))

Or you can try to implement it on that variable.

(haven't tried myself, but it is just a function re-mapping)

myvariable.__str__ = lambda s: """myClass({}, {}, {}, {}, {})""".format(
        myvariable.arg1, myvariable.arg2, myvariable.arg3, myvariable.arg4, myvariable.argN
    )

And then str(myvariable) might work

python print class text passed to a variable

1 Answers1