WindowsError: [Error 193] %1 is not a valid Win32 application in Python

Question

I wish to import liblas module in Python 2.7 on window 64bit. If I import the module with IDLE (Python GUI) I have no problem.

If I use PyScripter "PyScripter-v2.5.3-x64-Setup.exe" I get this error message.

>>> import liblas
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
  File "C:\Python27\lib\site-packages\liblas\__init__.py", line 2, in <module>
    from core import get_version
  File "C:\Python27\lib\site-packages\liblas\core.py", line 138, in <module>
    las = ctypes.CDLL(os.path.join(local_dlls, lib_name))
  File "C:\Python27\Lib\ctypes\__init__.py", line 365, in __init__
    self._handle = _dlopen(self._name, mode)
WindowsError: [Error 193] %1 is not a valid Win32 application

I have used liblas in PyScripter many times without problem and right now I can load all standard modules (e.g.: numpy, GDAL, etc.), but tonight (I need to finish an analysis!!!) I have this inconvenience.

Answer 1

Please make sure to have Python 2.7 64b edition :) or even though you are working on 64b OS, use the x86 (AKA 32b) edition of PyScripter

Edit 1 (following comments exchange w/ Gianni)

One should verify his/her entire Python process "composed" from same entities in the sense of 32b/64b builds (e.g. if your Python interpreter is 32b one, then it must use C types coming from C dll Python extensions which were compiled as 32b dlls).

In our example (liblas) one should go to C:\Python27\lib\site-packages\liblas , find the extension dll and see its type via dumpbin , here is some picture for demonstration :

Answer 2

This error can also be caused because the DLL that Python is attempting to run has been compiled on a newer version of C++. Make sure you are running the latest version of the Microsoft C++ Distribution.

You can see the version you are running in the Python terminal window (highlighted in bold)

Python 3.5.1 (v3.5.1:37a07cee5969, Dec 6 2015, 01:38:48) [MSC v.1900 32 bit (Intel)] on win32

Download here

https://www.microsoft.com/en-us/download/details.aspx?id=48145

Answer 3

You are probably using 64 bits Python. You should install the 32 bits version instead.