What is not working with my "map" usage?
Hi,
I want to add up all of the list elements. But when I use the "map" function,
it didn't seem to work as I expect. Could someone point out how "map" can be
applied here then?
def add_all_elements (*args):
total = 0
for i in args:
print(type(i))
print("i = %s" % i)
print("BEFORE total = %s" % total)
total += int(i)
print("AFTER total = %s\n" % total)
print("FINAL total = %s\n" % total)
return total
alist = ['2', '09', '49']
## this one works Okay
add_all_elements(*alist)
i = 2
BEFORE total = 0
AFTER total = 2
i = 09
BEFORE total = 2
AFTER total = 11
i = 49
BEFORE total = 11
AFTER total = 60
FINAL total = 60
## Why is this NOT Okay when I use map ?? What must I change ?
>>> list(map(add_all_elements,alist))
i = 2
BEFORE total = 0
AFTER total = 2
FINAL total = 2
i = 09
BEFORE total = 0
AFTER total = 9
FINAL total = 9
i = 49
BEFORE total = 0
AFTER total = 49
FINAL total = 49
[2, 9, 49]
Thanks,
Viet
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Re: Why emumerated list is empty on 2nd round of print?
On Thursday, September 6, 2018 at 12:12:20 PM UTC-7, David Raymond wrote: > The actual "enumerate" object is really just holding a current index and a > reference to the original list. So if you alter the original list while > you're iterating through it you'll see the changes. If you want a full copy > then you can just wrap it with list() > > Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 27 2018, 04:59:51) [MSC v.1914 64 bit > (AMD64)] on win32 > Type "help", "copyright", "credits" or "license" for more information. > >>> numList = [2, 7, 22, 30, 1, 8] > >>> aList = enumerate(numList) > >>> aList.__next__() > (0, 2) > >>> numList[1] = 5 > >>> aList.__next__() > (1, 5) > >>> aList2 = list(enumerate(numList)) > >>> aList2 > [(0, 2), (1, 5), (2, 22), (3, 30), (4, 1), (5, 8)] > >>> numList[3] = -12 > >>> aList2 > [(0, 2), (1, 5), (2, 22), (3, 30), (4, 1), (5, 8)] > >>> aList.__next__() > (2, 22) > >>> aList.__next__() > (3, -12) > >>> aList.__next__() > (4, 1) > >>> aList.__next__() > (5, 8) > >>> aList.__next__() > Traceback (most recent call last): > File "", line 1, in > StopIteration > >>> > > > -Original Message- > From: Python-list > [mailto:python-list-bounces+david.raymond=tomtom@python.org] On Behalf Of > Viet Nguyen via Python-list > Sent: Thursday, September 06, 2018 2:50 PM > To: python-list@python.org > Subject: Re: Why emumerated list is empty on 2nd round of print? > > On Thursday, September 6, 2018 at 10:34:19 AM UTC-7, Chris Angelico wrote: > > On Fri, Sep 7, 2018 at 3:26 AM, Viet Nguyen via Python-list > > wrote: > > >>>> numList > > > [2, 7, 22, 30, 1, 8] > > > > > >>>> aList = enumerate(numList) > > > > > >>>> for i,j in aList:print(i,j) > > > > > > 0 2 > > > 1 7 > > > 2 22 > > > 3 30 > > > 4 1 > > > 5 8 > > > > > >>>> for i,j in aList:print(i,j) > > > > > >>>> > > > > Because it's not an enumerated list, it's an enumerated iterator. > > Generally, you'll just use that directly in the loop: > > > > for i, value in enumerate(numbers): > > > > There's generally no need to hang onto it from one loop to another. > > > > ChrisA > > Thanks ChrisA. If I do this "aList = enumerate(numList)", isn't it stored > permanently in aList now? I see your point to use it directly, but just in > case I do need to hang onto it from one loop to another, then how is that > done? Anyway I think I'm ok and I got what I need for now. > -- > https://mail.python.org/mailman/listinfo/python-list Very clear and good examples! Thank you. -- https://mail.python.org/mailman/listinfo/python-list
Re: Why emumerated list is empty on 2nd round of print?
On Thursday, September 6, 2018 at 10:34:19 AM UTC-7, Chris Angelico wrote: > On Fri, Sep 7, 2018 at 3:26 AM, Viet Nguyen via Python-list > wrote: > >>>> numList > > [2, 7, 22, 30, 1, 8] > > > >>>> aList = enumerate(numList) > > > >>>> for i,j in aList:print(i,j) > > > > 0 2 > > 1 7 > > 2 22 > > 3 30 > > 4 1 > > 5 8 > > > >>>> for i,j in aList:print(i,j) > > > >>>> > > Because it's not an enumerated list, it's an enumerated iterator. > Generally, you'll just use that directly in the loop: > > for i, value in enumerate(numbers): > > There's generally no need to hang onto it from one loop to another. > > ChrisA Thanks ChrisA. If I do this "aList = enumerate(numList)", isn't it stored permanently in aList now? I see your point to use it directly, but just in case I do need to hang onto it from one loop to another, then how is that done? Anyway I think I'm ok and I got what I need for now. -- https://mail.python.org/mailman/listinfo/python-list
Why emumerated list is empty on 2nd round of print?
>>> numList [2, 7, 22, 30, 1, 8] >>> aList = enumerate(numList) >>> for i,j in aList:print(i,j) 0 2 1 7 2 22 3 30 4 1 5 8 >>> for i,j in aList:print(i,j) >>> -- https://mail.python.org/mailman/listinfo/python-list
Re: Is there a way to display source code for Python function?
On Thursday, October 2, 2014 10:34:15 PM UTC-7, Viet Nguyen wrote:
Hi,
When I am debug mode, is there some command which will help display the
source code for a Python function of interest? Much like you'd use info
proc to display contents of Tcl proc.
Thanks,
Viet
I tried this:
def func(a):
... a = 'abcd'
inspect.getsource(func)
Traceback (most recent call last):
File stdin, line 1, in module
File /sw/packages/python/current/lib/python2.7/inspect.py, line 701, in
getsource
lines, lnum = getsourcelines(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 690, in
getsourcelines
lines, lnum = findsource(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 538, in
findsource
raise IOError('could not get source code')
IOError: could not get source code
inspect.getsourcelines(func)
Traceback (most recent call last):
File stdin, line 1, in module
File /sw/packages/python/current/lib/python2.7/inspect.py, line 690, in
getsourcelines
lines, lnum = findsource(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 538, in
findsource
raise IOError('could not get source code')
IOError: could not get source code
What is wrong?
Thanks,
Viet
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Re: Is there a way to display source code for Python function?
On Thursday, October 2, 2014 10:47:28 PM UTC-7, Ian wrote:
On Thu, Oct 2, 2014 at 11:34 PM, Viet Nguyen
vhnguy...@yahoo.com.dmarc.invalid wrote:
Hi,
When I am debug mode, is there some command which will help display the
source code for a Python function of interest? Much like you'd use info
proc to display contents of Tcl proc.
Thanks,
Viet
You can use inspect.getsource() to get the source code for a function,
class, or module. The source must be available at whatever location
the module was imported from, and of course it won't work for anything
implemented in C.
Hi,
I tried:
def func(a):
a = 'abcd'
inspect.getsource(func)
Traceback (most recent call last):
File stdin, line 1, in module
File /sw/packages/python/current/lib/python2.7/inspect.py, line 701, in
getsource
lines, lnum = getsourcelines(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 690, in
getsourcelines
lines, lnum = findsource(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 538, in
findsource
raise IOError('could not get source code')
IOError: could not get source code
What is wrong?
Thanks,
Viet
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Re: Is there a way to display source code for Python function?
On Friday, October 3, 2014 12:48:08 AM UTC-7, Peter Otten wrote:
Viet Nguyen wrote:
On Thursday, October 2, 2014 10:34:15 PM UTC-7, Viet Nguyen wrote:
Hi,
When I am debug mode, is there some command which will help display the
source code for a Python function of interest? Much like you'd use info
proc to display contents of Tcl proc.
Thanks,
Viet
I tried this:
def func(a):
... a = 'abcd'
inspect.getsource(func)
Traceback (most recent call last):
File stdin, line 1, in module
File /sw/packages/python/current/lib/python2.7/inspect.py, line 701,
in getsource
lines, lnum = getsourcelines(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 690,
in getsourcelines
lines, lnum = findsource(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 538,
in findsource
raise IOError('could not get source code')
IOError: could not get source code
inspect.getsourcelines(func)
Traceback (most recent call last):
File stdin, line 1, in module
File /sw/packages/python/current/lib/python2.7/inspect.py, line 690,
in getsourcelines
lines, lnum = findsource(object)
File /sw/packages/python/current/lib/python2.7/inspect.py, line 538,
in findsource
raise IOError('could not get source code')
IOError: could not get source code
What is wrong?
The source of func is compiled and immediately discarded by the interactive
interpreter. inspect.getsource() only works if the source code is available
(as a module):
$ cat ham.py
def spam():
return 42
$ python3
Python 3.4.0 (default, Apr 11 2014, 13:05:11)
[GCC 4.8.2] on linux
Type help, copyright, credits or license for more information.
import ham, inspect
print(inspect.getsource(ham.spam))
def spam():
return 42
There is an alternative interactive interpreter called ipython that allows
you to retrieve a function definition:
In [1]: def foo():
...: return bar
...:
In [2]: %psource foo
def foo():
return bar
In [3]:
Thanks Peter!
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Is there a way to display source code for Python function?
Hi, When I am debug mode, is there some command which will help display the source code for a Python function of interest? Much like you'd use info proc to display contents of Tcl proc. Thanks, Viet -- https://mail.python.org/mailman/listinfo/python-list
Why captured match is displayed as part of pexpect .after ?
Hi,
If any is familiar with pexpect, please help to point out why my script seems
to fail to capture the desired text.
Here, I want to log into a server 172.27.161.19. Once I see Username: , I
will type in my userid admin.
The problem here is I have a list of keywords for pexpect to match before
returning the matched item for me. The list consists of following list items:
expects = ['yes', '.*Username: ', '.*login: |.*Login: ', 'SY-FAR-1',
'SY-FAR-1#', 'Password: |password: ', '.*Press RETURN to get started']
Here, it seems my script found Username: but it got displayed as PART OF
_pexpect_session.after (and this is what I don't understand). The .before
or .after data should consist of match before and after the desired keyword
only.
= Manual Execution ===
telnet 172.27.161.19
Trying 172.27.161.19...
Connected to 172.27.161.19.
Escape character is '^]'.
User Access Verification
Username: admin
Password:
SY-FAR-1en
SY-FAR-1#
=== Python Script Snippet ===
expects = ['yes', '.*Username: ', '.*login: |.*Login: ', 'SY-FAR-1',
'SY-FAR-1#', 'Password: |password: ', '.*Press RETURN to get started']
i = -1 # reset its value
print *step 1*before match, i = %s % i
self._pexpect_session.timeout = 80
cmd = admin
self._log(Executing CLI: '{0}'.format(cmd))
self._pexpect_session.sendline(cmd)
i = self._pexpect_session.expect(expects)
print *step 2* found index i = %s % i
print *step 3* after match, exec_cmd expects (%s) = % i, expects
print *step 4* exec_cmd match before: '%s' %
self._pexpect_session.before
print *step 5* exec_cmd match after: '%s' %
self._pexpect_session.after
=== Actual Script Output ==
*step1* before match, i = -1
Executing CLI: 'admin'
*step2* found index i = 1
*step3* after match, exec_cmd expects (1) = ['yes', '.*Username: ', '.*login:
|.*Login: ', 'SY-FAR-1', 'SY-FAR-1#', 'Password: |password: ', '.*Press RETURN
to get started']
*step4* exec_cmd match before: ''
*step5* exec_cmd match after: '
Username: '
Appreciate any input or explanation.
Thanks,
Viet
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Re: Why command os.popen works in python interactive mode but not in script debugger mode?
On Thursday, September 11, 2014 10:15:57 PM UTC-7, Viet Nguyen wrote:
Can anyone give me hint or reason why same command behaves differently in
debugger mode from interactive mode:
From interactive mode:
import os
p = os.popen('date')
p.read()
'Thu Sep 11 11:18:07 PDT 2014\n'
But from debugger mode in a script:
import os
(Pdb) p = os.popen('date')
*** SyntaxError: SyntaxError('invalid syntax', ('string', 1, 1, =
os.popen('date')))
Can anyone help me why there is syntax here?
Thanks,
Viet
Thank you for your help. That resolved the issue.
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Why command os.popen works in python interactive mode but not in script debugger mode?
Can anyone give me hint or reason why same command behaves differently in
debugger mode from interactive mode:
From interactive mode:
import os
p = os.popen('date')
p.read()
'Thu Sep 11 11:18:07 PDT 2014\n'
But from debugger mode in a script:
import os
(Pdb) p = os.popen('date')
*** SyntaxError: SyntaxError('invalid syntax', ('string', 1, 1, =
os.popen('date')))
Can anyone help me why there is syntax here?
Thanks,
Viet
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