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I couldn't get python working on desktop lean either, It wouldn't recognize that I had python2.7 installedbut I followed all the directions I could find. I wonder if they could do a quick video showing how to start from scratch and run a python backtest on desktop lean like the video they have for C#

Can you please paste the an error message? From the screen shots I am guessing its because you have installed anaconda-python; I think it needs plain python?

Could you please give us more details? 
What is the runtime error message?

 made a related question today:

I think I found my problem, I haven't figured out how to fix it yet, although I'm close. I keep getting this message:

I figured out that I didn't follow the python readme.md as close as I thought. First I created a system path variable to my python 2.7 install location because I had forgotten to do that. Then I read this instruction closer: 

Rename `Lean\packages\QuantConnect.pythonnet._version_\build\Python.Runtime.win` to `Lean\packages\QuantConnect.pythonnet._version_\lib\Python.Runtime.dll`.  I didn't realise that by rename it also meant that I had to move it to the lib folder. Then I made sure that python was working in visual studio by reading some stuff here and making python 2.7 the default python environment. I tested the python interactive prompt in visual studio to confirm that it worked.

THEN I redownloaded and used a fresh version of lean. Still got the error.

Now I did a little more digging into what I think is the true cause:

Unable to find an entry point named 'PyUnicodeUCS4_FromUnicode' in DLL 'python27'.

I just checked and my python is UCS-2. I just installed it from the python website so I had no idea that I had to specify for it to install encoded a certain way. But I'm going to try and resintall python 2.7with --enable-unicode=ucs4 somewhow and see if that works. I will report back later.

Hmm nope, can't get it

OK so I got it working. I uninstalled everything, including visual studio and python and reinstalled it. I also made SURE to copy over the .dll to the right spot and deleted the DLL that was there initially. Part of the reason I think it was giving me problems was because I am on 64bit windows and I had installed multiple versions of python installed, for both 64bit and 32bit. This time I let Visual basic install python 2.7 64 bit during the installation instead of doing it myself. It installed it to a folder at C:\Python27amd64. I had to point the path in my system to C:\Python27amd64, not C:\Python27 like the readme says (which is the 32bit version by default).

Hi ,

thanks you everybody for your help.

 logs and screenshot : https://groups.google.com/forum/#!topic/lean-engine/mQeSrNsZ6

My install: python integration option checked during VS2017 community installation.

I didn't install python 2.7 in first intention because ananconda was already install and managing packages is very easy (pandas and dependencies in one click!)

PS: I have also an another problem with  environment": "backtesting-desktop" that I have fixed.

https://groups.google.com/forum/#!topic/lean-engine/vnE-tXRMKo0

I haven't tested my python2.7 anaconda environnement VS integration (https://docs.microsoft.com/en-us/visualstudio/python/python-environments)... It could be the problem

I am glad you made it. 
Like Jared said, that runtime error tells us that you were using the wrong dll (unfortunatelly we need a dll for each OS).

Chris Alteras a user in the slack channel manage to get it working with Anacondas:

Jared: slack channel infos are for linux user (mono install and linux command like ln -s ...)

finally I did it.

My steps:

- install python x64

(don't forget path add option )

- open console (cmd) and install panda: py -2.7 -m pip install pandas

- download lean from github

- open with VS2017 , select solution, click right and select restore nuget package

- open python environment and select Python2.7 x64 (maybe not mandatory)

- follow github instruction carefully( rename .win to .dll and paste in lib folder , etc...)

- run ...

- If you want GUI: * click solution, properties, project dependencies and click on Quanconnect.Views

* in config.json :  "environment": "backtesting-desktop"

* AND replace in config.json  ..../Debug/QuantConnect.Views.exe by .../Release/QuantConnect.Views.exe

you should have:

 "desktop-http-port": "1234",
  "desktop-exe": "../../../UserInterface/bin/Release/QuantConnect.Views.exe"

- don't forget user id ( see quantconnect , MyAccount)

Hi Guys, After reading all above I still cant get it. Could anyone provide some info on what I am doing wrong here? The following text is coming up red when i run the lean launcher

20170904 13:11:35 Error:: Loader.TryCreatePythonAlgorithm():  System.DllNotFoundException: Unable to load DLL 'python27': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
   at Python.Runtime.Runtime.Py_IsInitialized()
   at Python.Runtime.Runtime.Initialize()
   at Python.Runtime.PythonEngine.Initialize(IEnumerable`1 args, Boolean setSysArgv)
   at Python.Runtime.PythonEngine.Initialize()
   at QuantConnect.AlgorithmFactory.Loader.TryCreatePythonAlgorithm(String assemblyPath, IAlgorithm& algorithmInstance, String& errorMessage) in C:\QC_lean\Lean-master\AlgorithmFactory\Loader.cs:line 164
20170904 13:11:36 Error:: Engine.Run():  System.Exception: Loader.TryCreatePythonAlgorithm(): Unable to import python module ../../../Algorithm.Python/BasicTemplateAlgorithm.py. Unable to load DLL 'python27': The specified module could not be found. (Exception from HRESULT: 0x8007007E): try re-building algorithm.
   at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Engine.cs:line 111

Lucas: check in c:\python27 if you have python27.dll

If not try to copy C:\Windows\System32\ python27.dll (or C:\Windows\SysWOW64)  into c:\python27

Chris you are a champion. That fixed that problem, cheers!
Now I am up to the error (this pops up in the gui, but there is red in the cmd too)

2017-09-05T07:27:12.1211034Z Error Algorithm.Initialize() Error: Loader.TryCreatePythonAlgorithm(): Unable to import python module ../../../Algorithm.Python/BasicTemplateAlgorithm.py. An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B): try re-building algorithm. Stack Trace:    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Engine.cs:line 111
    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\QC_lean\Lean-master\Engine\Engine.cs:line 111

The first few lines in my config.json looks like:

  "environment": "backtesting-desktop",// "live-paper", "backtesting", "live-interactive", "live-interactive-iqfeed"

  // algorithm class selector
  "algorithm-type-name": "BasicTemplateAlgorithm",

  // Algorithm language selector - options CSharp, FSharp, VisualBasic, Python, Java
  //"algorithm-language": "CSharp",
  "algorithm-language": "Python",

  //Physical DLL location
  //"algorithm-location": "QuantConnect.Algorithm.CSharp.dll",
  "algorithm-location": "../../../Algorithm.Python/BasicTemplateAlgorithm.py",
  //"algorithm-location": "QuantConnect.Algorithm.FSharp.dll",
  //"algorithm-location": "QuantConnect.Algorithm.VisualBasic.dll",
  //"algorithm-location": "QuantConnect.Algorithm.Java.dll",

sorry lucas, i was quite busy these day.

step1:check project depencies: select solution level, click right, select properties

check if Views is included

step2: correct Debug with Release in config.json (read carefully my previous post)

Hi Chris, Thanks for getting back to me.

I started on a fresh pc. Running win 10 with MSVS 2017 community and python x64 2.7 that comes preinstalled with visual studio. I am still failing dismally.

The error is the same as the original post: Unable to import python module ../../../Algorithm.Python/BasicTemplateAlgorithm.py. Unable to find an entry point named 'PyUnicodeUCS4_FromUnicode' in DLL 'python27'.

Attached is a screenshot of my path location

You mentioned python.dll in syswow or system32. I have one python.dll in each (not sure if that even matters, I have tried C:\Python27amd64\python.dll (with both and with none, I still get the same error)

Lucas that error probably means you've copied the wrong DLL in place. UCS2 is the mac/linux version of the DLL -- UCS4 is the window one which it needs too work. I guess you didn't *precisely* copy the file: (note the paths)

The version is 1.0.4.4 at the moment:

I am pretty sure I have done that part correctly (I have read  the instructions and attempted about 10 installs now).

Maybe I am not installing python properly?
.

Sorry Lucas Alex tells me he can't get it going on Windows either (fine on Mac/Linux). We'll figure it out it today and update the install readme.

1. Install Visual Studio Community: (if you don't have it already).
1.1 Visual Studio 2017 Community edition which can be downloaded free from: https://www.visualstudio.com. Visual Studio comes with Python (if you install Python Tools for Visual Studio) but it doesn't seem to add Python to the system path. We'll need to reinstall python manually. If you already have VS installed you should be able to skip this step.

2. Install Python:
2.1 Use the Windows x86-64 MSI installer from https://www.python.org/downloads/release/python-2713/
2.2 When asked to select the features to be installed, make sure you select "Add python.exe to Path"
2.3 Once installed confirm the python27.dll is in place in C:\Windows\System32.
2.4 Add python27.dll to the system path 
2.4.1 Right mouse button on My Computer. Click Properties.
2.4.2 Click Advanced System Settings -> Environment Variables -> System Variables
2.4.3 On the "Path" section click New and enter the python27.dll path, in our example this was "C:\Windows\System32"
2.5 Install pandas and its dependencies.

3. Setup LEAN:
3.1 Download LEAN github clone, or downloading the zip. If downloading the zip - unzip to a local pathway.
3.2 Prepare Python.Runtime DLL. This is needed to run LEAN with Python.
3.2.1 Delete the existing files in \Lean\packages\QuantConnect.pythonnet.1.0.4.4\lib
3.2.2 Using windows you'll need to copy the\Lean\packages\QuantConnect.pythonnet.1.0.4.4\build\*Python.Runtime.win* file into the ..\lib\ directory with the name: Python.Runtime.dll

4 Run LEAN:
4.1 Run with a basic C# algorithm first to make sure it works (using the default credentials, just press F5).
4.1.1 You should see this exit successfully with a list of the algorithm statistics and 1 trade.
4.2 Update the config to run the python algorithm:

"algorithm-type-name": "BasicTemplateAlgorithm",
"algorithm-language": "Python",
"algorithm-location": "../../../Algorithm.Python/BasicTemplateAlgorithm.py",

4.2.1 You should see the same result of 4.1.1. 

There are steps that i follow Lucas. So it should work. I hope for you.

Test first  backtesting in console mode. after that reread my post for gui backtesting.

Maybe Alexandre can explain us a better way than fixing path in config.json (ie how to compile the missing debug version of QuantConnectView.exe).

We need to change the solution "Property Pages":
Right click the solution in the Solution explorer, then select Properties. 

Change Release for Debug and click the Ok button.
Rebuild the solution and run.

Great thank you guys, I got it running

Hi,

Another Quantopian refugee here...  I have limited experience with VS and building on Windows, so please be gentle :). I've been following the instructions in this thread and elsewhere, but am unable to get past the 'Unable to load DLL python2.7' problem (details below). Note that I did not touch the windows system PATH environment variable, because c:\windows\system32 was already listed there.  I also tried copying python27.dll from c:\windows\system32 into c:\python27, but this did not fix the problem.  Thanks.

Robert

Backtrace:

20170920 09:11:30 Trace:: JOB HANDLERS:
20170920 09:11:30 Trace::          DataFeed:     QuantConnect.Lean.Engine.DataFeeds.FileSystemDataFeed
20170920 09:11:30 Trace::          Setup:        QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler
20170920 09:11:30 Trace::          RealTime:     QuantConnect.Lean.Engine.RealTime.BacktestingRealTimeHandler
20170920 09:11:30 Trace::          Results:      QuantConnect.Lean.Engine.Results.BacktestingResultHandler
20170920 09:11:30 Trace::          Transactions: QuantConnect.Lean.Engine.TransactionHandlers.BacktestingTransactionHandler
20170920 09:11:30 Trace:: Config.GetValue(): send-via-api - Using default value: False
20170920 09:11:30 ERROR:: Algorithm.Initialize() Error: Loader.TryCreatePythonAlgorithm(): Unable to import python module ../../../Algorithm.Python/BasicTemplateAlgorithm.py. Unable to load DLL 'python2.7': The specified module could not be found. (Exception from HRESULT: 0x8007007E): try re-building algorithm. Stack Trace:    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\Lean-master\Engine\Engine.cs:line 111
    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\Lean-master\Engine\Engine.cs:line 111

I had this same problem. I managed to fix it by looking at what environment my actual VS was in. I found out that even though my path was python 2.7, my VS was running Python 3.5 which was causing the problem. By setting the development environment in VS to 2.7 it fixed the problems. 

Thanks, Atish. Interesting, it looks like my VS Community 2017 edition doesn't include Python.  Is that others' observation?

Go Tools-->Python-->Python Environment.    That was where I found my issue. I also inlucded the python install when I installed VS Community 2017, so not sure what happens if you don't select that option. 

Okay, looks like there's possibility of adding it after the fact.  Trying now...

I did Tools-->Choose Toolbox Items... and was able to install Python 2.7 (64-bit), which is now listed as my default environment under Tools-->Python-->Python Environments. Unfortunately, I continue to have the same error (unable to find DLL python2.7). 

Click on configure environment to make sure that it is pointing to the correct files. I would do a quick google search to look into how to configure python environments in VS, because that is literally what I did to get it to work, so I only sorta knew what I was doing. 

Okay, thanks.

Noob question, what does "Prepare Python.Runtime DLL. This is needed to run LEAN with Python." means?

"Prepare Python.Runtime DLL. This is needed to run LEAN with Python." is the subsection.
It means you have to follow the instructions below. :-)
- Delete the existing files in \Lean\packages\QuantConnect.pythonnet.1.0.4.4\lib
- Using windows you'll need to copy the\Lean\packages\QuantConnect.pythonnet.1.0.4.4\build\*Python.Runtime.win* file into the ..\lib\ directory with the name: Python.Runtime.dll

any managed to get it to work? i read and tested all the different one yet still get the same error. 

2017-11-16T07:23:15.5399263Z Error Algorithm.Initialize() Error: Loader.TryCreatePythonAlgorithm(): Unable to import python module ../../../Algorithm.Python/BasicTemplateAlgorithm.py. Unable to load DLL 'python2.7': The specified module could not be found. (Exception from HRESULT: 0x8007007E): try re-building algorithm. Stack Trace:    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\Lean-master\Engine\Engine.cs:line 111
    at QuantConnect.Lean.Engine.Setup.ConsoleSetupHandler.CreateAlgorithmInstance(AlgorithmNodePacket algorithmNodePacket, String assemblyPath) in C:\Lean-master\Engine\Setup\ConsoleSetupHandler.cs:line 94
   at QuantConnect.Lean.Engine.Engine.Run(AlgorithmNodePacket job, AlgorithmManager manager, String assemblyPath) in C:\Lean-master\Engine\Engine.cs:line 111
 

Generally speaking please post LEAN / open source issues which we can't debug through QuantConnect.com to the open source group -- https://groups.google.com/forum/#!forum/lean-engine

Incase of error UCS4

When Run LEAN  at the first time, 
   Need to update  QuantConnect.pythonnet (Nuget package)  from 1.0.4.4 => 1.0.5.1  

Instruction

         1.  Rebuild Solution (CSharp)

         2. Tools -> Nuget package manager -> Manage Nuget package for Solution -> (Wait few minutes for checking update) -> Updates -> Check QunatConnect.pythonnet 1.0.5.1 -> Update

         3. Then try to run BasicTemplateAlgorithm.py (Python)

- Unable to load DLL 'python2.7': 
   Problem come from Python.Runtime.dll and Win x64

   Solution:

   Load pythonnet from the following URL and select environment DebugWin x64 or ReleaseWin x64 to build solution
   Remanrk: 

    Default environment,  DebugMono is not working for Win x64

then Copy Python.Runtime.dll   =>   C:\Lean\Lean-2.4.0.1\packages\QuantConnect.pythonnet.1.0.5.1\lib

    Testing:

       testing via run cmd C:\pythonnet-master\src\console\bin\nPython.exe, if you got python command prompt it's working.

     So, right now,  Ready to run Lean with Python.

- Unable to load DLL 'python2.7': 
   Problem come from Python.Runtime.dll and Win x64

   Solution:

     1. Load pythonnet from the following URL and rebuild with following configuration

select 

    -  "solution configuration" either  => DebugWin or ReleaseWin 
     - "solution platform"  =>  x64

then

      2. Build -> Rebuild Solution

   Remanrk: 

    Default solution configuration,  DebugMono is not working for Win x64

 3.CopyPython.Runtime.dll   =>   C:\Lean\Lean-2.4.0.1\packages\QuantConnect.pythonnet.1.0.5.1\lib

 Testing:

 1. run cmd C:\pythonnet-master\src\console\bin\nPython.exe, if you got python command prompt that's mean it's work good.

    So, right now,  Ready to run Lean with Python.

sorry for duplicate post. 

Team

I spent 5 hours on this and leaned the following.

Step 1:
Follow these instructions from Alexandre post above Steps 1 to 4 above.

Steps 2: May give you some trouble if you are not used to playing wiht python like me.

2.5 Install pandas and its dependencies.

Simple go to your start menu and run the Anaconda promt.

Step 2: 

Make sure the QuantConnect.Algorithm.PythonTools project is pointed to the right version of Python 2.7

VS2017 default is 3.6 not 2.7.  So load both with the Visual Studio Installer...
Visual Studio Installer: Can be found on the menu at \Tools\Get Tools and Features
Under indivudal componnects click both Python2 and Python 

To make sure you are running the correct version of Python...
Right click the Python Environment segment of the QuantConnect.Algorithm.PythonTools project.
Select add and Remove Python Environments, and select Python 2.6.

Spo this is what worked for me on a fresh install of VS2017.

Thank you for the detailed post Mike; If you're able please update the python readme with your findings and I'll give you a free live subscription =) 

Hello Mike, So you used Anacondas installation? or why you run Anaconda Prompt?

The following is the command that you need to run

And according to the document for lpthw (which just uses a fork of web.py), you can run :

Then to run the application you will just need to do:

Hi, I am on a Mac, and I am also having problems with the python module... It seems also with the C# module when trying to load the first solution in installation "QuantConnect.Lean.sln". 

• I have Python2.7 installed with libpython2.7.dylib in /usr/lib. 
• I have prepared Python.Runtime.dll for Mac as per the instructions. 
• Here is a screenshot of the exact errors I am getting:

Here is (part of) an explanation: https://docs.microsoft.com/en-us/visualstudio/python/installing-python-support-in-visual-studio#visual-studio-2017

I've spend about 6 hours working on this and I am pretty much back where I started....

In any case, although after a lot of manual installing of extensions in Visual Studio Code, I am able to run the QuantConnect.Lean.sln without a problem with the two project files mentioned above (QuantConnect.Algorithm.PythonTools.pyproj and QuantConnect.VisualStudio17Plugin.csproj), but I get an error about reference assemblies. 

After installing mono (and realizing I needed to install C# on my new computer) I tried Visual Studio for Mac again... 

After deleting the two aforementioned projects from QuantConnect.Lean.sln (meaning the lines of code that begin/end with "Project/End Project") the .sln file runs and returns the following error:

Note: I modified the QuantConnect.Lean.Launcher.csproj file            <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion> to reflect my version of .Net. (Current .Net Core for Mac is v2.1.4).

There is reference to a similar issue with the Linux/Ubuntu installation in the readme.md file, so I tried that and this is what I got:

FINALLY... when I completely DELETE the version, the solution runs with no errors and I get all of the files built (except for the F# and the Python folders). Meaning now in QuantConnect.Lean.Launcher.csproj I have            <TargetFrameworkVersion></TargetFrameworkVersion>. There is no target framework specified.... 

And so, finally I have STATISTICS OUTPUT running the  Algorithm.CSharp/BasicTemplateAlgorithm.cs.

I think the things to note for Visual Studio for Mac is make sure to:

• Install Homebrew: terminal command /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

   

• Install C# using Homebrew: $ brew install scriptcs

   

• Download & install Mono at http://www.mono-project.com/download/
• Open QuantConnect.Lean.sln using an editor like TextEdit or XCode (as the code for the sln files for some reason is not visible with VS for Mac) and delete line 55-56:

• You may also have to delete lines 51-52, but I think that can be avoided, as at the end of the installation readme.md there is a section "QuantConnect plugin" that addresses these lines of code

• Finally, delete the target version argument from QuantConnect.Lean.Launcher.csproj. In other words, change

to

Not sure how stable these last changes are... and I think they have gone outside of the scope of this thread... perhaps it should be moved/copied to a new thread for Mac Installation. 

Thanks!

Finally, it seems that the Project for the VisualStudioPlugin cannot be loaded because the project tries to import a file that does not exist, namely on Line 3 of VisualStudioPlugin/QuantConnect.VisualStudio17Plugin.csproj: 

I did a thorough search in the terminal and the file doesn't exist anywhere:

Thanks Alix Claire Erie -- good investigating! In future please post LEAN questions/issues/tutorials like this to the google group where it will benefit most people: https://groups.google.com/forum/#!forum/lean-engine

I was having a similar issue where VS would reconize Python but I was still getting an error that Lean could not find the .dll. I tried the above and reinstalled everything with no luck. Howerver, I was able to get it to work by going to Tools > NuGet Package Manager > Manage NuGet Packages for Solution then updated the packages and reinstalled QuantConnect.pythonnet to the entire project. I was able to build it and run a debug with no further issues. I spent many hours trying to figure this out and hope I can save someone else the time and headache!

I want to run a python script from within IntelliJ IDEA passing a file list as a parameter. I'm using menu Run->Edit Configurations->Script Parameters to define a file list using wildcards like: "../examples/*.jpg"

Inside the code I'm iterating the file list using a for loop like

Although the script executes fine from terminal, IDEA throws a file not found exception:

I suppose this makes sense (my theory) since there is no shell involved to expand the command line argument into a file list prior passing it to the script.

There is an answer in a similar question here: Pycharm and sys.argv arguments The relevant answer using wildcards is https://stackoverflow.com/a/41003295/7521854 but it is not working. (If I had enough rep I'd commented on this answer, sorry)

Any suggestion will make me happy!

PS: running OSX 10.11.6 (El Capitan)

@Alix Claire Erie, I have installed visual studio code for MAC, and installed extensions support for Python, .Net core tools and C#, and installed .Net SDK. When I opened QuantConnect.Lean.sln file, click Debug - start without debuging, select envirement as .Net core, there was no any feedback. How can I run Lean in Visual Studio Code for MAC for Python?

li li In the end I did not set up the local version of QC. Lean was a bigger project than I was able to join. I continued by using the online version of QuantConnect, in C#. 

For anyone still struggling to get the Python GUI to work correctly, I was able to solve the problem after a few hours.  Here's what I did:

1) Follow the config.json steps as shown in the tutorial.

2) Download Python 3.6.8.  I also have 3.7 and anacondas, but to my best knowledge LEAN only works with 3.6 for now.

    - Make sure you include the location in PATH, but also take the python.exe, pythonw.exe and python36.dll and copy them to your System32 folder.

    - Unblock C:\Program Files (x86)\LEAN\Lean-master\UserInterface\QuantConnect.Views by right clicking the file and going to properties

3) In Visual Studios at the top go to Tools -> Python -> Python Environments (Ctrl+K).

    - Set Python 3.6 as your default

    - Open the Powershell window and run pip install for numpy, pandas, seaborn and any other libraries you need to import.

You should now be able to build and run the python basic template.  This is as far as I've gotten personally.  I know I need to download some data files for my other algorithms, but hopefully this saves others some time.

Hi Shyer,

Thanks for sharing your experience! Just want to add:

1. Here is how you install a specific version of python with anaconda (i.e. 3.6.6):

Currently we only support Python 3.6, so if you are using python 3.7 please make sure to downgrade to 3.6 or install python 3.6 separately.

2. For mac users, please read our instruction of running Lean with python algorithms.

Thanks for your support.

Setting up QuantConnect Lean for Python

Algorithm.Python/readme.md has instructions for running Python algorithms with QuantConnect locally. But if that didn't work for you, try the following (Windows only):

Note: As of May 2020 QuantConnect supports Python 3.6, and is not compatible with Python 3.7 or later.

1. Install Visual Studio Community Edition

   • Check Python development

2. Install Anaconda (it is a distribution of the Python and R programming languages for data science, and includes Jupiter Notebooks and many other packages)

3. From the Start menu run Anaconda Prompt

4. Create a new environment. You need to do this only once.

   conda create -y --name QuantConnect python=3.6 anaconda
conda activate QuantConnect

5. Check the QuantConnect environment is activated

   conda env list

Now every time you wanted to open QuantConnect project do this:

1. From start Menu open Anaconda Powershell Prompt (QuantConnect)

2. Set PYTHONHOME environment variable

   $env:PYTHONHOME="$env:USERPROFILE\anaconda3\envs\QuantConnect"

3. Open QuantConnect solution in Visual Studio

   cd C:\repos\Lean
start .\QuantConnect.Lean.sln

4. Modify Launcher\config.json to have the following settings:

   "environment": "backtesting",
"algorithm-type-name": "BasicTemplateAlgorithm",
"algorithm-language": "Python",
"algorithm-location": "../../../Algorithm.Python/BasicTemplateAlgorithm.py",

5. Run the project with F5

The above should work, but I could not find how to persist the environment so we can run the solution file by double-clicking on it. Setting PYTHONHOME in user env vars did not work.

I have followed all instructions and steps to implement LEAN in Python wth VS but keep facing many errors when building the project file in VS, Errors screenshot attached in below link:

https://drive.google.com/file/d/17a59ULDmdRuymL4r6EIx8WvJh3_0AS7U/view?usp=sharing

Hi John Addae ,

I have answered your question in this thread:
Using Lean with Visual Studio 2017 and Anaconda3 #4174