How to debug in Pycharm - python

Is there something special I need to debug in Pycharm?
I have the following code:
def main():
print "Hello World"
if __name__ == "__main__":
main()
and I have breakpoints on each. I hit Debug and it gives me some windows and prints both lines even though I have breakpoints on each. Is there any kind of indicator when a breakpoint is hit?
I have seen in other posts something about how you must setup your configuration first? But none of the posts seem to mention how. Here is my configuration
Please do not link me here: https://www.jetbrains.com/pycharm/help/debugging.html I have read it and do not understand what I need to do. I keep getting reffered to lines such as:
In the Project Structure dialog box, configure the roots, dependencies
and libraries to be passed to the interpreter .
I am new to python and am not sure what I should be inputting into the boxes.
So my question is really.
Is Pycharm supposed to debug python out of the box?
How do I setup Pycharm to debug python if not.
I am using the latest python 2.7.9 a fresh install of a few minutes ago.

You set breakpoints in the gutter by clicking a wee bit to the right of the line numbers (if visible)...
...and run under the "Debug" context (it's the green icon that looks like a bug of some kind).

Well it turns out I am just a idiot. Though I have seen people in the debug menu complaining about the same problem.
You are debugging. The breakpoint does not change to indicate you have hit that line like visual studio. Instead one of your lines will change a light blue (depending on your theme) to indicate you are debugging that line.

Related

What is a "line marker" icon in PyCharm?

What is this "line marker" icon in the gutter in PyCharm IDE?
When does it appear exactly?
I looked up but this doesn't explain much about the icon itself.
It represents the entry point into the application - the line that is first invoked when you run the code.
You have some options when you click on it to run the code in a number of ways, for example with profiling or debugging.
The "Line Marker" (or green run icon) in the gutter is added by PyCharm to special lines the IDE considers as runnable. This is not only the case for lines containing a Top level script enviorment but also frequent with executable test functions from testing frameworks, for example with pytest among others.
The PyCharm IDE detects these automatically (for example by prefixing a function name with test and having a testing framework configurered). One good example of this is the following thread where the IDE makes a mistake detecting a line as runnable, see PyCharm: FooTestCase is no test, but FooTest is.

how to clear the screen in pycharm

I know these are questions: this and this and this. I have tried all of these methods in pycharm, but they either a) not work or b) I get a weird character on my screen, that looks like a 0 with diagonal line going through it. I can't copy it for some reason, so I can't show you.
For instance this:
import os
from time import sleep
print("lots of text")
sleep(5)
os.system('cls')
What should happen in the above is tht the message should be displayed for 5 seconds then disappear, but all I get is that weird character... In contrast when I ran my python program from command line, it worked as expected i.e. the screen cleared. I am very confused.
So my questions are:
Why don't any of them work in pycharm?
What does work in pycharm?
Ok, so, I have been having this problem as well — after scouring the internet, the os commands work BUT you need to enable the terminal emulator.
In the PyCharm toolbar, click Run, Edit Configurations, and the toggle for "Emulate Terminal in Output Console" should be under Execution in the pop up. Emulate Terminal toggle
I had to get help from the PyCharm team on this one, so here's to them responding at lightning speed.
Answer
The cls command doesn't work on a standard pycharm project because it is an IDE and certain os commands don't work in the same way it would with the windows command line.
There is currently no way to clear the console output in PyCharm, other than to manually do it by using the cls command through the terminal in PyCharm or through a keyboard shortcut set through the pycharm preferences menu. You can try to emulate a keyboard shortcut, but this would be difficult, and unless you absolutely need it, I would not recommend clearing the terminal output after a program is run.
References and Additional Links
https://teamtreehouse.com/community/clear-screen-for-pycharm-as-if-it-were-on-console-or-cmd
I don't know in which version of PyCharm this was introduced. I guess it must have been after this question was asked.
The way to clear the PyCharm Python Console is by using the context menu. Right mouse click in the upper part of the console (where the lines with >>> prompts are closer together) and select Clear All.
Alse see this PyCharm Support Community article.
Incidentally, none of the questions linked to in the OP's original post relate to PyCharm and do not answer the OP's question.
cls only temporarily clears it. Next command brings back all previous messages. The best option is to right click on the Terminal and choose Clear Buffer

Is there "Edit and Continue" in PyCharm? Reload code into running program like in Eclipse / PyDev?

Hi all Python developers!
In Eclipse with PyDev it is possible to edit a Python file while debugging. On save, the PyDev debugger will reload the updated code into the running program and uses my new code. How can I do the same thing in JetBrains PyCharm (using Community Edition)?
Eclipse / PyDev writes an output like this when I do that:
pydev debugger: Start reloading module: "MyWidget" ...
pydev debugger: Updated function code: <function close at 0x055F4E70>
pydev debugger: reload finished
I searched settings and web and could not find any hint. Very glad about any idea. Thx.
Edit: I found out in Eclipse/PyDev one has to be in debug mode to be able to use this feature. I tested in PyCharm, but there was no reload done.
PyCharm does not support edit and continue in either the community edition or the professional edition but here is a workaround that I have found while debugging.
Since you can run arbitrary code in the console and/or the expression evaluator, in a lot of cases, you can execute changes to the code without having to restart the application. This isn't exactly like edit-and-continue (which is a feature I really like in Visual Studio and should be part of Pycharm) but it goes a long way towards avoiding having to restart the program from scratch after a change to see if the new code works as expected.
Let me illustrate a couple of the techniques I use:
Let's say you have the following code (with a couple of typos/bugs to illustrate the techniques)
test_value = [10,9,8,7,6,55,4,3,2,1]
for i in range(0,10):
if test_value[i] == i:
print "found the value: " + i
If you run this code, first it errors because you can't print string plus integer but also I wanted to match on 5, not have 55 in the array. So here we go.
Set a break point on the for statement like this and run the code in the debugger.
When it breaks into the debugger, you realize that it should be 5 not 55. Rather than restarting, you can change line 1 to test_value = [10,9,8,7,6,5,4,3,2,1] then select the line, right click and choose Execute Line in Console... which will change the value of test_value to be the array with a 5. Now, the if statement on line 4 becomes true on the value 5. This will then trigger the syntax error on line 5.
Now if you want to make sure you have the syntax correct you can change line 5 to print "found the value: " + str(i), select the line and choose Evaluate Expression... from the right button context menu. When you click Evaluate, the result will show up either in the dialog (or in this case, since it is a print command, in the console)
Now that I've fixed these two issues, I can run the code successfully on the second pass rather than possibly multiple passes it might have taken if I didn't use these techniques. These techniques really pay off if you find a bug deep in the code where it took a while to set up.
Obviously, this is a very contrived example, but hopefully this shows how you can use both Evaluate Expression... and Execute Line in Console... to your advantage while debugging without having to restart your application each time you find a bug in the code.
Also, if you happen to be using Django, PyCharm (professional) will re-launch the server if you make changes to the code. So if you are looking at your web page and notice a problem, you can make a change to the code and switch back to the web page and as you do, either the running application or the debugged application will re-launch and the new code will be running when you refresh the page. Again, not really edit-and-continue but a pretty rapid way to make a change and test.
After all I found a useful and acceptable workaround for my question. It works in PyCharm Community Edition 3.1.2 and I assume it will do in commercial edition as well. I tested on a mid-scale project using Python 2.7.6, PySide (Qt) with one main window and 20+ widgets, tabs, whatever. Follow these steps...
Work in PyCharm on a python project :-)
Execute your code in Debug mode (did not tried Release so far)
Edit some code in one your modules imported during the life of your program
Make your program pause. To achieve this, you can click the "Pause" button of in PyCharms Debug view and then any place in your applications main window where it would need to do something (for example on a tab header). If you have a long a running task and no UI, you may place a breakpoint in a place your program often comes by.
In the Debug view, switch to the Console tab. There is a button on the left Show command line. Click this.
In the console, type in reload(MyModifiedModule) if this call fails, write import MyModifiedModule and try again.
Click resume in PyCharm.
Try the code you fixed.
There are some restrictions on this... It won't fix changes in your main method or main window, cause it won't be created again. In my tests I could not reload widgets from Qt. But it worked for classes like data containers or workers.
May the force be with you as you try this and do not hesitate to add your experiences.
I have the commercial version of PyCharm and just tried testing a simple python script. The script is the following:
for i in range(0,100):
print i
I ran the code in debug mode and placed a break point at the "print i" statement. When the debugger stopped during the first iteration I changed the code to look like this:
for i in range(0,100):
print i
print 'hello'
PyCharm did not reload/re-compile the altered script. Given this simple test my best guess would be that PyCharm does not dynamically reload .py files.
You can add hot reloading features by installing Reloadium plugin.
https://plugins.jetbrains.com/plugin/18509-reloadium
Example use (gif)
It also works without pycharm.
More details:
https://github.com/reloadware/reloadium

Python IDLE. Auto-complete/Show completions not working

IDLE is being very dodgy as to when it will actually show an Auto-complete menu. As of late it hasn't been working at all, or, more specifically, only works during an interactive session.
I've been using Code Blocks for C, and have gotten really used to the very nice auto-complete features, so it's a bit frustrating not having them -- especially while trying to learn a new frame work and what class is associated with which methods, etc, etc..
Is there an easy fix to get IDLE auto-complete working again? I'm using python version 2.7.
Is there perhaps a simple editor I should look into? I've tried Vim, which was a little too heavy for my simple needs, Ninja, which I couldn't get to work for anything, and Sublime text 2, which I couldn't get my wxpython stuff to play with. What would a nice option be? Anything similar to Code Blocks would be cool, although, I'd be perfectly happy with IDLE if it would consistently work!
REQUESTED CLARIFICATION:
OK, so it seems I may have some of my terminology backwards. By non-interactive, I mean, for instance, right clicking on a python file and selecting "edit with IDLE". This brings up what I guess could be described as a text editor. You can enter all you code here. Once ready, you then hit F5, or select Run, and it launches (what I've been referring to as) the interactive terminal. It's here that you can type in code, press return, and instantly have that code evaluated.
What my question is referring to it the former, the part of IDLE where you edit the code. Sometimes while typing, after a . it will display the available methods, or after an open parenthesis it'll give hints as to the values expected. but the thing is, sometimes it does these things, sometimes it doesn't.
The only thing i found so far is that if an editing session of IDLE is connected with python shell (called "interactive mode" in the question, i.e. after an attempt to run the edited script) then "non-interactive" IDLE can autocomplete based on values in interactive window. For example, if I type
a = [];
a.appen
and then hit < Tab > it will do nothing, but if I previously type
a = []
in corresponding python shell, IDLE will autocomplete correctly.
So my only suggestion is import same modules with same names in python shell window in order to make them "visible" for non-interactive IDLE editor.
I had the same problem with IDLE, because I want to learn Qt and therefore autocompletion is very useful.
As it says in the settings of IDLE, you can trigger the autocomplete with "Control + Space", e.g. after a "QtGui.". Then a menu opens where you can arrow-scroll through the entries.
using the 'IDLE Editor window', you need to save and execute your code first.
The application running, turn back to the Editor window to use the auto-completion.
In my case, I had to open Options menu -> Extensions tab on the editor and look to make sure AutoComplete and other relevant options were enabled. They actually were, but by just clicking on 'Apply' even though I dint have to change anything did the trick for me.
Sometimes it has to do with the time you have to wait to get a suggestions.
When you go to options > extensions > general at completions popup wait you can change it to about 500ms.
In my case it was 2000ms by default.

How to get debugging of an App Engine application working?

I've got 10+ years in C/C++, and it appears Visual Studio has spoilt me during that time. In Visual Studio, debbuging issimple: I just add a breakpoint to a line of code, and as soon as that code is executed, my breakpoint triggers, at which point I can view a callstack, local/member variables, etc.
I'm trying to achieve this functionality under App Engine. I assume that is possible?
All the searching I've done to this point has led me to using Pydev in Eclipse. As best I can tell, I am successfully launching my simple 'hello world' program in Debug mode.
But the IDE doesn't even seem to have an option to set a breakpoint? I must be missing something.
I've googled long and hard about this, but am having no luck. Most results trace back to the same old threads that don't deal directly with my issue.
Can anyone shed some light on how you get basic debugging setup using Pydev/Eclipse with App Engine?
Alternatively, if there's an easier way to debug App Engine than using Pydev/Eclipse, I'd love to hear about it.
Thanks in advance.
In fact setting a breakpoint in eclipse is very easy. You have two options:
In the grey area next to your line numbers, doubleclick or right mouseclick -> toggle breakpoint.

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