global name 'self' is not defined

[Evan]

Hi

I have a short script that makes 2 calls to methods in another script
as follows:

import canPlaces as canp

callOne=canp.addMe(3,5)
callTwo=canp.estocStn()

The 2 methods in the second script are:

def addMe(a,b)
sumAb=a+b
return sumAb

def estocStn():
estoc={'lat':29.15,'lon':-15.667,'place':'ESTOC'}
return estoc

Why is it that the first call works fine, but the second tells me
'global name 'self' is not defined'? What I want is to have the
dictionary 'estoc' available in my calling script.

Thanks, Evan

 

[George Sakkis]

Hi

I have a short script that makes 2 calls to methods in another script
as follows:

import canPlaces as canp

callOne=canp.addMe(3,5)
callTwo=canp.estocStn()

The 2 methods in the second script are:

def addMe(a,b)
sumAb=a+b
return sumAb

def estocStn():
estoc={'lat':29.15,'lon':-15.667,'place':'ESTOC'}
return estoc

Why is it that the first call works fine, but the second tells me
'global name 'self' is not defined'? What I want is to have the
dictionary 'estoc' available in my calling script.

Thanks, Evan

Please post examples that reproduce the error; what you posted doesn't
even refer to "self" at all.

George

 

[Felipe Almeida Lessa]

Why is it that the first call works fine, but the second tells me
'global name 'self' is not defined'? What I want is to have the
dictionary 'estoc' available in my calling script.

Well, you have not posted the code that is causing the problem,
nowhere in your mail there's a reference to "self".

 

[Evan]

In answer to the 2 replies, I had no references anywhere to 'self'. In
order to post my code I rewrote 2 scripts containing just the relevant
parts of the problem; these work. However, they are identical to my
original code. So I have deleted the 'old' script2 and renamed the new
one, and no problem. I don't know why it worked with one and not the
other when they are identical, but I have what I want now.

Thanks for your replies.

-Evan

 

[John Machin]

In answer to the 2 replies, I had no references anywhere to 'self'. In
order to post my code I rewrote 2 scripts containing just the relevant
parts of the problem; these work. However, they are identical to my
original code.

This is (putting it mildly) somewhat difficult to believe. If true, it
would indicate a rather severe bug in Python. Identical as determined
how?

When you ran your original code and it gave an error, Python would have
told you where the error occurred, on which line of which file, as in
the following example:

C:\junk>copy con noself.py
def foo():
return self
^Z
1 file(s) copied.

C:\junk>\python25\python
Python 2.5 (r25:51908, Sep 19 2006, 09:52:17) [MSC v.1310 32 bit
(Intel)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
| >>> import noself
| >>> noself.foo()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "noself.py", line 2, in foo <<<=== location of error-causing
line
return self <<<=== contents of error-causing line
NameError: global name 'self' is not defined

And you could have told us that information. No, should. Adding to what
others have already said:

When asking a question about an error message:
(a) Provide code (abbreviated if necessary) that causes the error.
Don't retype it; copy/paste the code that you actually ran.
(b) Show the full traceback and error message. Again, use copy/paste.

So I have deleted the 'old' script2 and renamed the new
one, and no problem. I don't know why it worked with one and not the
other when they are identical, but I have what I want now.

No problem? Sorry, it just transformed itself. Here is a precise
definition of the transformed problem: "I don't know why it worked with
one and not the other".

And what you want now doesn't include enlightenment? Thrashing madly at
problems with a sledgehammer may sometimes (but not always) make them
appear to go away faster than a methodical problem-solving approach
would take, but it's rather a short-tem "gain".

HTH,
John

 

[Bjoern Schliessmann]

So I have deleted the 'old' script2 and renamed the new one, and
no problem.

Pity. Next time try using diff (or something similar).

Regards,


Björn

 

[Evan]

The problem seems to be with ipython, which I have been using to run
these scripts. My calling script (call.py) is:

import canaryPlaces_test as canp

sum=canp.addme(3,5)
print sum
estoc=canp.estocStn()
print estoc



The problem script is this one, named canaryPlaces_test.py:

def estocStn():
estoc={'lat':29.15,'lon':-15.667,'place':'ESTOC'}
return estoc

def addme(a,b):
sumAb=a+b
return sumAb



The ok script, named canaryPlaces.py, is identical apart from a comment
at the top of one of them. Here is output from 'diff' for the two of
them:

@suse212:~/python/mapping> diff canaryPlaces_test.py canaryPlaces.py
1c1
<
---

# canaryPlaces evan@suse212:~/python/mapping>



From the command line I get what I expect calling either

canaryPlaces_test.py or canaryPlaces.py:

@suse212:~/python/mapping> python call.py
8
{'lat': 29.149999999999999, 'place': 'ESTOC', 'lon': -15.667}
evan@suse212:~/python/mapping>



However -> Using ipython and calling canaryPlaces.py is fine, but
calling canaryPlaces_test.py gives:

In [97]: %run call
8
---------------------------------------------------------------------------
exceptions.NameError Traceback (most
recent call last)

/home/evan/python/mapping/call.py
2
3 sum=canp.addme(3,5)
4 print sum
----> 5 estoc=canp.estocStn()
6 print estoc
/home/evan/python/mapping/canaryPlaces_test.py in estocStn()
5 return estoc
6
7 def addme(a,b):
8 sumAb=a+b
9 return sumAb
NameError: global name 'self' is not defined
WARNING: Failure executing file: <call.py>

In [98]:


On my system this error is repeatable.

-Evan

 

[Dennis Lee Bieber]

The problem seems to be with ipython, which I have been using to run
these scripts. My calling script (call.py) is:

One: Does ipython generate/use an equivalent to Python's .pyc/.pyo
files.

Two: have you deleted any such file, so the import is forced to
rebuild them (if the date stamps/magic number/whatever somehow got out
of sync, it may not be importing what you think it is).

import canaryPlaces_test as canp

sum=canp.addme(3,5)
print sum
estoc=canp.estocStn()
print estoc

Three: Have you tried embedding the test logic at the bottom of the
imported module (if __name__ == "__main__": do the tests) and trying to
run those directly rather than importing.

--
Wulfraed Dennis Lee Bieber KD6MOG
(e-mail address removed) (e-mail address removed)
HTTP://wlfraed.home.netcom.com/
(Bestiaria Support Staff: (e-mail address removed))
HTTP://www.bestiaria.com/

 

[Evan]

Hi Dennis, to answer your questions:

1) So far as I can see ipython generates .pyc files.
2) This morning I ran the scripts, and got the same problem using
ipython as in my earlier post. I then deleted the .pyc file, ran the
calling script and this time it works. I then replaced the .pyc file I
had deleted, expecting to have the problem again, but no.
3) I've tried your suggestion, and it works fine.

A few questions: Why does python use the double underscore (__main__ or
if __name__)? I've only been using python for about 3 weeks, and I see
this syntax a lot, but haven't found an explanation for it so far?
Also, as I understand , the .pyc files should be updated every time you
change and run the equivalent .py file?

Thanks, Evan

 

[Fredrik Lundh]

A few questions: Why does python use the double underscore (__main__ or
if __name__)? I've only been using python for about 3 weeks, and I see
this syntax a lot, but haven't found an explanation for it so far?

to quote the language reference, "System-defined names. These names are
defined by the interpreter and its implementation (including the
standard library)". see:

http://effbot.org/pyref/reserved-identifier-classes

</F>

 

[Dennis Lee Bieber]

A few questions: Why does python use the double underscore (__main__ or
if __name__)? I've only been using python for about 3 weeks, and I see
this syntax a lot, but haven't found an explanation for it so far?
Also, as I understand , the .pyc files should be updated every time you
change and run the equivalent .py file?

Bottom up:

.pyc/.pyo are generated during an import IF the interpreter, after
checking various magic numbers in the header and date-stamps determines
that the .py is newer. If something glitched your clock, it is possible
that an old .pyc still looks newer and gets pull in. There have also
been cases of the Python installer (on Windows, and using the
ActiveState build, at least) putting .pyc/.pyo in front of .py in the
executable extension list -- meaning an older .pyc would be run instead
of accessing the newer .py...

When a module is run directly (not imported), no .pyc/.pyo files are
generated. A module run directly gets the name "__main__" by the
interpreter (an imported module gets the name used to import it). The

if __name__ == "__main__":

is a way for a module to be used as a standalone program, or test mode,
by putting the test driver or standalone interface into the "if" block.
When the module is imported, the "if" is false, so none of the code in
it is executed.
--
Wulfraed Dennis Lee Bieber KD6MOG
(e-mail address removed) (e-mail address removed)
HTTP://wlfraed.home.netcom.com/
(Bestiaria Support Staff: (e-mail address removed))
HTTP://www.bestiaria.com/