Advanced tutorial for rospy services?

Question

Please don't link me to the beginner tutorial. This is beyond the provided examples. Let's define MySrv.srv as:

geometry_msgs/Point p
geometry_msgs/Vector3 v
float64 f
bool b
---
bool success

Then I perform the following:

p = Point()
v = Vector3()
req = MySrvRequest(p, v, -1, False)                                                                                                                                                                                                                                                       
rsp = myServiceProxy(req)

I always get the error: DeserializationError cannot deserialize: 'Point' object attribute 'x' is read-only. What am I doing wrong?

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Originally posted by seanarm on ROS Answers with karma: 753 on 2018-05-15

Post score: 0

Answer 1

I think your service structure is too complex for the calling method described in the tutorials. This question from a while may help solve your problem. You may have to construct the request object beforehand and then call the service.

Hope this helps.

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Originally posted by PeteBlackerThe3rd with karma: 9529 on 2018-05-15

This answer was ACCEPTED on the original site

Post score: 1

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Original comments

Comment by gvdhoorn on 2018-05-15:
Isn't the OP already doing that? req is an explicitly a priori created request instance.

Comment by PeteBlackerThe3rd on 2018-05-15:
True, they are. I miss-read that one.

Comment by seanarm on 2018-05-15:
This helped me out still. Switching to the empty MySrvRequest constructor and filling in the attributes via individual assignment worked fine.

Comment by PeteBlackerThe3rd on 2018-05-15:
Glad you got it working