PyCall: Modifying an array in Python

General Usage
3

Thank you for this. That works for me now. But one thing I don’t understand yet:

app = pyeval("lambda x: x.append(1)")
x = Float64[] 
app(x)

throws an error

ERROR: PyError (:PyObject_Call) <type 'exceptions.AttributeError'>
AttributeError("'numpy.ndarray' object has no attribute 'append'",)
  File "PyCall.jl", line 1, in <lambda>

But doesn’t PyVector(x) convert to a numpy array as well? What is the difference?