Parsing hl7 message line by line using python

Question

i want to read my hl7 messages from a file line by line and parse them using python. I'm able to read But my problem is in parsing. It parses only my 1st line of the file and prints till the 2nd line but does not parses futhur because it tells that my 2nd line is not hl7. And the error shown is

h=hl7.parse(line)
File "C:\Python27\lib\site-packages\hl7\parser.py", line 45, in parse
plan = create_parse_plan(strmsg, factory)
File "C:\Python27\lib\site-packages\hl7\parser.py", line 88, in create_parse_plan
assert strmsg[:3] in ('MSH')
AssertionError

for the code:

with open('example.txt','r') as f:
    for line in f:
       print line
       print hl7.isfile(line)
       h=hl7.parse(line)

So how do i make my file a valid one. This is example.txt file

MSH|^~\&|AcmeMed|Lab|Main HIS|St.Micheals|20130408031655||ADT^A01|6306E85542000679F11EEA93EE38C18813E1C63CB09673815639B8AD55D6775|P|2.6|
EVN||20050622101634||||20110505110517|
PID|||231331||Garland^Tracy||19010201|F||EU|147 Yonge St.^^LA^CA^58818|||||||28-457-773|291-697-644|
NK1|1|Smith^Sabrina|Second Cousin|
NK1|2|Fitzgerald^Sabrina|Second Cousin|
NK1|3|WHITE^Tracy|Second Cousin|
OBX|||WT^WEIGHT||78|pounds|
OBX|||HT^HEIGHT||57|cm|

Answer 1

I had a similar issue and came up with this solution that works for me.

In short, put all your lines into an object and then parse that object. (Obviously you can clean up the way I checked to see if the object is made yet or not, but I was going for an easy to read example.)

a = 0
with open('example.txt','r') as f:
    for line in f:
       if a == 0:
           message = line
           a = 1
       else:
           message += line
h=hl7.parse(message)

Now you will have to clean up some \r\n depending on how the file is encoded for end of the line values. But it takes the message as valid and you can parse to your hearts content.

for line in h:
    print(line)

MSH|^~\&|AcmeMed|Lab|Main HIS|St.Micheals|20130408031655||ADT^A01|6306E85542000679F11EEA93EE38C18813E1C63CB09673815639B8AD55D6775|P|2.6|
EVN||20050622101634||||20110505110517|
PID|||231331||Garland^Tracy||19010201|F||EU|147 Yonge St.^^LA^CA^58818|||||||28-457-773|291-697-644|
NK1|1|Smith^Sabrina|Second Cousin|
NK1|2|Fitzgerald^Sabrina|Second Cousin|
NK1|3|WHITE^Tracy|Second Cousin|
OBX|||WT^WEIGHT||78|pounds|
OBX|||HT^HEIGHT||57|cm|

Answer 2

Tagging onto @jtweeder answer, the following code worked for prepping my HL7 data.

In notepad++, I noticed that each line ended with LF, but did not have CR. It seems as though this hl7 library requires \r, not \n.

filename = "TEST.dat"  
lines = open(filepath + filename, "r").readlines()  
h = '\r'.join(lines)