PulpSolverError：PuLP：嘗試在Python 2.7中執行glpsol時出錯

Question

我通過iPython筆記本和Python 2.7在OS X上運行PuLP 。 glpk利用安裝brew install homebrew/science/glpk和紙漿通過安裝pip install pulp 。

但是我在Python中遇到錯誤：

---------------------------------------------------------------------------
PulpSolverError                           Traceback (most recent call last)
<ipython-input-15-689fef0dd94f> in <module>()
      1 # Solve the problem
----> 2 status = prob.solve(GLPK(msg=0))
      3 

/Users/x/anaconda/envs/data/lib/python2.7/site-packages/pulp/pulp.pyc in solve(self, solver, **kwargs)
   1641         #time it
   1642         self.solutionTime = -clock()
-> 1643         status = solver.actualSolve(self, **kwargs)
   1644         self.solutionTime += clock()
   1645         self.restoreObjective(wasNone, dummyVar)

/Users/x/anaconda/envs/data/lib/python2.7/site-packages/pulp/solvers.pyc in actualSolve(self, lp)
    364                              stderr = pipe)
    365             if rc:
--> 366                 raise PulpSolverError("PuLP: Error while trying to execute "+self.path)
    367         else:
    368             if os.name != 'nt':

PulpSolverError: PuLP: Error while trying to execute glpsol

這是觸發此錯誤的代碼：

from pulp import *

#Variables
x = LpVariable('x')
y = LpVariable('y')

# Problem
prob = LpProblem('problem', LpMinimize)

# Constraints
prob += x + y <= 1
prob += x <= 1
prob += -2 + y <= 4

# Objective function to minimize
prob += 

# Solve the problem
status = prob.solve(GLPK(msg=0))

導致錯誤的原因是什么，以及如何解決？

Answer 1

如果你跑

pulp.pulpTestAll()

你可能會看到這樣的一行：

Solver pulp.solvers.GLPK_CMD unavailable

如果是這樣，你所要做的就是在linux上安裝glpk-utils軟件包。 如果你成功了，你應該可以打電話

glpsol

從命令行也是。

Answer 2

我在Ubuntu中遇到了同樣的錯誤，這解決了它。

make install之后必須發出以下命令：

sudo ldconfig

Ldconfig為最新的共享庫創建必要的鏈接和緩存。

https://lists.gnu.org/archive/html/help-glpk/2013-09/msg00018.html