What is it?

A python package enabling user to call all the epanet programmers toolkit functions within python scripts.

Installation

Windows:

Use a Python ditribution that comes with a c copiler (use WinPython or PythonXY)

pip install epanettools

POSIX (e.g. Linux, OS-X):

Download source archive (zip file), extract and run (as root)

[sudo] python setup.py install

or just type

[sudo]  pip install epanettools

Usage:

>>> import os, pprint
>>> pp=pprint.PrettyPrinter() # we'll use this later.
>>> from  epanettools.epanettools import EPANetSimulation, Node, Link, Network, Nodes, \
... Links, Patterns, Pattern, Controls, Control # import all elements needed
>>> from epanettools.examples import simple # this is just to get the path of standard examples
>>> file = os.path.join(os.path.dirname(simple.__file__),'Net3.inp') # open an example
>>> es=EPANetSimulation(file)

Node information

>>> len(es.network.nodes)
97
>>> list(es.network.nodes)[:5] # just get indexes of nodes
[1, 2, 3, 4, 5]
>>> [es.network.nodes[x].id for x in list(es.network.nodes)[:5]] # Get ids of first five nodes.
['10', '15', '20', '35', '40']
>>> n=es.network.nodes
>>> n[1].id
'10'
>>> n[94].id
'Lake'
>>> n['10'].index # get the index of the node with id '10'
1

Now links

>>> m=es.network.links
>>> len(m)
119
>>> m[1].id
'20'
>>> m[3].id
'50'
>>> m[119].id
'335'

Information about connectivity

>>> [m[1].start.id,m[1].end.id] # get the two ends of a link
['3', '20']
>>> [m[118].start.id,m[118].end.id]
['Lake', '10']
>>> sorted([i.id for i in n['169'].links]) # get the links connected to a node.
['183', '185', '187', '211']

Types of links and nodes

>>> pp.pprint(Node.node_types) # these are the type codes for nodes.
{'JUNCTION': 0, 'RESERVOIR': 1, 'TANK': 2}
>>> n[94].node_type
1
>>> n[1].node_type
0
>>> n['2'].node_type
2
>>> pp.pprint(Link.link_types) # these are the type codes for links
{'CVPIPE': 0,
 'FCV': 6,
 'GPV': 8,
 'PBV': 5,
 'PIPE': 1,
 'PRV': 3,
 'PSV': 4,
 'PUMP': 2,
 'TCV': 7}
>>> m['335'].link_type # Pump
2
>>> m['101'].link_type # PIPE
1
>>> m[1].link_type #
1
>>> [y.id for x,y in m.items() if y.link_type==Link.link_types['PUMP']] # get ids of pumps
['10', '335']
>>> [y.id for x,y in n.items() if y.node_type==Node.node_types['TANK']] # get ids of tanks
['1', '2', '3']

Network properties are available (even before we run the simulation)

>>> d=Link.value_type['EN_DIAMETER']
>>> print("%.3f" % es.network.links[1].results[d][0])
99.000

Get some results of simulation.

>>> es.run()
>>> p=Node.value_type['EN_PRESSURE']
>>> print("%.3f" % es.network.nodes['103'].results[p][5] )
59.301
>>> d=Node.value_type['EN_DEMAND']
>>> h=Node.value_type['EN_HEAD']
>>> print("%.3f" % es.network.nodes['103'].results[d][5])
101.232
>>> print("%.3f" % es.network.nodes['103'].results[h][5])
179.858
>>> d=Link.value_type['EN_DIAMETER']
>>> print("%.3f" % es.network.links[1].results[d][0])
99.000
>>> es.runq() # run water quality simulation
>>> q=Node.value_type['EN_QUALITY']
>>> print("%.3f" % es.network.nodes['117'].results[q][4])
85.317
>>> e=Link.value_type['EN_ENERGY']
>>> print("%.5f" % es.network.links['111'].results[e][23])
0.00685

Some advanced result queries

>>> print("%.3f" % min(es.network.nodes['103'].results[p])) # minimum recorded pressure of node '103'
44.169
>>> n=es.network.nodes
>>> # All nodes recording negative pressure.
>>> sorted([y.id for x,y in n.items() if min(y.results[p])<0])
['10']
>>> # Nodes that deliver a flow of more than 4500 flow units
>>> d=Node.value_type['EN_DEMAND']
>>> j=Node.node_types['JUNCTION']
>>> sorted([y.id for x,y in n.items() if ( max(y.results[d])>4500 and y.node_type==j )])
['203']

Legacy Interface

Do not use the following methods unless for compatibility!

>>> import os
>>> from epanettools import epanet2 as et
>>> from epanettools.examples import simple
>>> file = os.path.join(os.path.dirname(simple.__file__),'Net3.inp')
>>> ret=et.ENopen(file,"Net3.rpt","")

Example 1:

Retrieve simulation properties.

Basic properties of the network

>>> ret,result=et.ENgetcount(et.EN_LINKCOUNT)
>>> print(ret)
0
    >>> print(result)
    119
>>> ret,result=et.ENgetcount(et.EN_NODECOUNT)
>>> print(ret)
0
>>> print(result)
97
    >>> node='105'
    >>> ret,index=et.ENgetnodeindex(node)
    >>> print(ret)
    0
    >>> print ("Node " + node + " has index : " + str(index))
    Node 105 has index : 12

Get the list of nodes

>>> ret,nnodes=et.ENgetcount(et.EN_NODECOUNT)
>>> nodes=[]
>>> pres=[]
>>> time=[]
>>> for index in range(1,nnodes):
...     ret,t=et.ENgetnodeid(index)
...     nodes.append(t)
...     t=[]
...     pres.append(t)
>>> print (nodes)       #doctest: +ELLIPSIS
...                     #doctest: +NORMALIZE_WHITESPACE
    ['10', '15', '20', '35', '40', '50', '60', ..., '275', 'River', 'Lake', '1', '2']

Get nodes indexes on either side of a link with given index

>>> et.ENgetlinknodes(55) # note the first item in the list should be ignored.
[0, 5, 46]

>>> patId = "NewPattern";
>>> ret=et.ENaddpattern(patId)
>>> print(ret)
0
>>> import numpy as np
>>> patFactors=np.array([0.8, 1.1, 1.4, 1.1, 0.8, 0.7, 0.9, 0.0, 0.8, 0.8, 0.0, 0.0],
...                      dtype=np.float32)
>>> ret,patIndex=et.ENgetpatternindex(patId)
>>> print(patIndex)
6
>>> et.ENsetpattern(patIndex, patFactors)
0
>>> et.ENgetpatternid(6)[1]
'NewPattern'
>>> et.ENgetpatternlen(6)
[0, 12]
>>> [round(et.ENgetpatternvalue(6,i)[1],3) for i in range(1,12+1)]
[0.8, 1.1, 1.4, 1.1, 0.8, 0.7, 0.9, 0.0, 0.8, 0.8, 0.0, 0.0]
>>> et.ENsetpatternvalue(6,9,3.3)
0
>>> [round(et.ENgetpatternvalue(6,i)[1],3) for i in range(1,12+1)]
[0.8, 1.1, 1.4, 1.1, 0.8, 0.7, 0.9, 0.0, 3.3, 0.8, 0.0, 0.0]

Hydraulic Simulation

>>> et.ENopenH()
0
>>> et.ENinitH(0)
0
>>> while True :
...    ret,t=et.ENrunH()
...    time.append(t)
...    # Retrieve hydraulic results for time t
...    for  i in range(0,len(nodes)):
...        ret,p=et.ENgetnodevalue(i+1, et.EN_PRESSURE )
...        pres[i].append(p)
...    ret,tstep=et.ENnextH()
...    if (tstep<=0):
...        break
>>> ret=et.ENcloseH()
>>> print([round(x,4) for x in pres[0]])   #doctest: +ELLIPSIS
...                                         #doctest: +NORMALIZE_WHITESPACE
    [-0.6398, 40.1651, 40.891, 41.0433, ..., 0.569, -0.8864, 0.2997]

Pressure at the node ‘10’

>>> ret,ind=et.ENgetnodeindex("10")
>>> print (ind)
1
>>> print([round(x,4) for x in pres[ind+1]]) # remember epanet count starts at 1.
...                                          #doctest: +ELLIPSIS
...                                          #doctest: +NORMALIZE_WHITESPACE
    [12.5657, 12.9353, 13.4351, 14.0307, ..., 13.1174, 13.3985, 13.5478]