Install Python with Inno Setup

Question

I am creating a setup from C# program successfully with Inno Setup. To run this program I need Python. Until today I asked my customers to install Python manually, since some customers are not always following my installation guide, I am getting often questions from them. Now I want to simplify the installation, so that everything is done automatically. I need to set:

Install path of Python: C:\Python\Python3.5.2
Installation for all users
Set the global environment variable for Python C:\Python\Python3.5.2
If all this already exist no installation needed

I tried to do this with this code, but I didn't had any success. Normal Python installation is starting unfortunately.

[Run]
Filename: "{app}\deploy\python-3.5.2.exe"; \
    Parameters: "/i ""C:\Python\Python-3.5.2"" /qb! ALLUSER=1 ADDLOCAL=ALL"; \
    WorkingDir: "{app}\deploy"; Flags: 32bit; Check: python_is_installed

[Code]

function python_is_installed() : Boolean;
var
  key : string;
begin
   { check registry }
   key := 'software\Python\Python-3.5.2\InstallPath';
   Result := not RegValueExists(HKEY_LOCAL_MACHINE, Key, '');  
end;

What do I do wrong?

BR Stefan

Martin Prikryl · Accepted Answer · 2017-02-20 16:58:05Z

1

You seem to be using a completely wrong sent of command line arguments (for Windows Installer?).

See Python documentation for correct command-line arguments of the Python Windows installer:
https://docs.python.org/3/using/windows.html

You probably want something like this:

/passive InstallAllUsers=1 TargetDir=C:\Python\Python3.5.2 PrependPath=1

edited Feb 20, 2017 at 16:58

answered Feb 19, 2017 at 17:10

Martin Prikryl

205k64 gold badges559 silver badges1.1k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Martin Prikryl · Accepted Answer · 2021-01-21 07:15:59Z

1

Another problem is that the installation check in the code section is not working as expected. RegValueExists() always returns false with an empty value name. That means your check function always returns false even if the key exists. This is the reason why Python installation is run always, even if Python is already installed.

To check for the existence of a key, not a value, use the function RegKeyExists().

See How to check if specific Python version is installed in Inno Setup?

edited Jan 21, 2021 at 7:15

Martin Prikryl

205k64 gold badges559 silver badges1.1k bronze badges

answered Jan 19, 2021 at 12:12

Georg W.

1,36611 silver badges29 bronze badges

1 Comment

Martin Prikryl Over a year ago

The RegValueExists(Root, Key, '') checks for an existence of the default value in the key. I do not have that specific Python version installed. But checking the versions I do have installed, they indeed have the default value in their InstallPath subkeys. So it's quite possible that OP's code works in that particular respect. Otherwise, your code seems better in respect to testing Python installation. But I still believe you are not answering OP's question. Consider starting a new question about detecting Python installation and self-answer it. I'll be happy to upvote your posts then.

Collectives™ on Stack Overflow

Install Python with Inno Setup

2 Answers 2

Comments

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Linked

Related