Sympy and mpmath imported but still ImportError

[Alexander Tille]

Hi guys,
I don't understand the relationship of sympy and mpmath.
As I followed the instructions of http://docs.sympy.org/latest/install.html#mpmath 
I installed mpmath and sympy as you can see in the following lines.

$ pip install sympy
Collecting sympy
Requirement already satisfied: mpmath>=0.19 in /home/atille/.anaconda2/lib/python2.7/site-packages (from sympy)
Installing collected packages: sympy
Successfully installed sympy-1.0


my code includes the following lines

import sys
import mpmath 
from sympy import *
from sympy import solve
from sympy import init_printing

but results in this error message

Traceback (most recent call last):
  File "./algebraic_calculation_model_6_rescaled.py", line 4, in <module>
    import sympy.mpmath 
  File "/usr/lib/python2.7/dist-packages/sympy/__init__.py", line 20, in <module>
    raise ImportError("SymPy now depends on mpmath as an external library. "
ImportError: SymPy now depends on mpmath as an external library. See http://docs.sympy.org/latest/install.html#mpmath for more information.

Can you explain my mistake?

Thank you in advance.

[Björn Dahlgren]

On Tuesday, 8 November 2016 15:52:40 UTC+1, Alexander Tille wrote:

Hi,
 

Traceback (most recent call last):
  File "./algebraic_calculation_model_6_rescaled.py", line 4, in <module>
    import sympy.mpmath 

/.../

Can you explain my mistake?

If you change that line to "import mpmath" (and change any code referencing it accordingly) it should be fine.

Best regards,
Björn

[Alexander Tille]

Hi,
I checked also this solution.

Traceback (most recent call last):

  File "./algebraic_calculation_model_9_rescaled_D-I-with_rd.py", line 4, in <module>
    import mpmath
ImportError: No module named mpmath

I tried to add the anaconda directory to the python path but it doesn't work because I get the same error message
     PYTHONPATH="${PYTHONPATH}:/home/atille/.anaconda2/lib/python2.7/site-packages"
     export PYTHONPATH


It works fine if I copy the mpmath library from my anaconda directory into the directory where I execute the code.
In this case I comment the import mpmath command.
But this soultion is really ugly.

[Aaron Meurer]

If you are using the Anaconda Python, neither of these should be necessary.

Aaron Meurer

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[Alexander Tille]

Ok! Thank you for this answer.

I still used the standard python interpreter.
I changed it to

#!~/.anaconda2/bin/python

and it works.

Thank you for your explanations.

Alex