UOPY Example - Working with JSON
Making the connection
The following code is a simple example to connect to a local U2 Database. In this example I am connecting to UniData, but the code would work the same against UniVerse, the only thing you would need to modify is the server and account settings.
In [1]:
import uopy
import getpass
user = input("Enter user name? ")
passwd = getpass.getpass("Enter Password? ")
def makeconnection(user, password):
config = {
'user': user,
'password': passwd,
'service': 'udcs',
'account': 'C:\\\\U2\\\\ud82\\\\XDEMO',
'encoding': 'GB18030',
'pooling_on': 'False'
}
thissession = uopy.connect(**config)
return thissession
session = makeconnection(user, passwd)
print(str(session))
Enter user name? mrajkowski
Enter Password? ········
<uopy._session.Session object {'host': 'localhost', 'account': 'C:\\\\U2\\\\ud82\\\\XDEMO', 'port': 31438, 'timeout': 100, 'service': 'udcs', 'encoding': 'GB18030', 'ssl': False, 'user': 'mrajkowski', 'password': ''} at 0x000001D44571DB80>
Read in a JSON document
Note that to in this example, I am limiting my discussion on how to create and consume JSON. I am using the TOJSON keyword to generate the JSON from a U2 File, in this case the MEMBERS file in the XDEMO account.
In [2]:
import pprint
cmd = uopy.Command("LIST MEMBERS FIRST_NAME LAST_NAME CITY STATE ZIP SAMPLE 3 TOJSON")
st = cmd.run()
out = cmd.response
print(out)
{
"MEMBERS":[
{"_ID" : "0011","FIRST_NAME" : "Dwayne","LAST_NAME" : "Kennedy","CITY" : "Bristol","STATE" : "Idaho","ZIP" : "33563"
},
{"_ID" : "0384","FIRST_NAME" : "Mitra","LAST_NAME" : "Bruce","CITY" : "St. Paul","STATE" : "Alaska","ZIP" : "66340"
},
{"_ID" : "0757","FIRST_NAME" : "Steve","LAST_NAME" : "Seagle","CITY" : "Edmunston","STATE" : "West Virginia","ZIP" : "51671"
}
]
}
Converting the string to a Python Dictionary with eval() function
Note that while this is an easy way, it could be exploited by hackers.
In [3]:
data = eval(out)
print(type(data))
pprint.pprint(data)
<class 'dict'>
{'MEMBERS': [{'CITY': 'Bristol',
'FIRST_NAME': 'Dwayne',
'LAST_NAME': 'Kennedy',
'STATE': 'Idaho',
'ZIP': '33563',
'_ID': '0011'},
{'CITY': 'St. Paul',
'FIRST_NAME': 'Mitra',
'LAST_NAME': 'Bruce',
'STATE': 'Alaska',
'ZIP': '66340',
'_ID': '0384'},
{'CITY': 'Edmunston',
'FIRST_NAME': 'Steve',
'LAST_NAME': 'Seagle',
'STATE': 'West Virginia',
'ZIP': '51671',
'_ID': '0757'}]}
As you can see with one command, I changed the string to a python dictionary object. The problem arises when you are not in control of what is being passed into the eval function.
In [4]:
code_string = 'print("This is an example of the eval() function executing commands.")'
eval(code_string)
This is an example of the eval() function executing commands.
Using the Python json module
A better way of dealing with the json string is to marshell it to a Python dictionary with the built-in json module.
In [5]:
import json
try:
jdata = json.loads(out)
print(type(jdata))
pprint.pprint(jdata)
except:
print("problem with json")
<class 'dict'>
{'MEMBERS': [{'CITY': 'Bristol',
'FIRST_NAME': 'Dwayne',
'LAST_NAME': 'Kennedy',
'STATE': 'Idaho',
'ZIP': '33563',
'_ID': '0011'},
{'CITY': 'St. Paul',
'FIRST_NAME': 'Mitra',
'LAST_NAME': 'Bruce',
'STATE': 'Alaska',
'ZIP': '66340',
'_ID': '0384'},
{'CITY': 'Edmunston',
'FIRST_NAME': 'Steve',
'LAST_NAME': 'Seagle',
'STATE': 'West Virginia',
'ZIP': '51671',
'_ID': '0757'}]}
Note that by using the json.loads method, we prevent a non-json string from causing a problem.
In [6]:
try:
jdata = json.loads(code_string)
print(type(jdata))
pprint.pprint(jdata)
except:
print("problem with json")
problem with json
Once you have the json, you can display some of the information
In [7]:
mydict = dict()
for each in jdata["MEMBERS"]:
print(each["_ID"] + " is for " + " " + each["LAST_NAME"] + ", " + each["FIRST_NAME"])
mydict[each["_ID"]] = each
0011 is for Kennedy, Dwayne 0384 is for Bruce, Mitra 0757 is for Seagle, Steve
Lets look at one of the Python Dict objects a bit closer
In [8]:
this_obj = mydict["0011"]
pprint.pprint(this_obj)
print()
print("With the Python dict object, we can access each named-value pair, for example just the CITY:")
print(this_obj["CITY"])
{'CITY': 'Bristol',
'FIRST_NAME': 'Dwayne',
'LAST_NAME': 'Kennedy',
'STATE': 'Idaho',
'ZIP': '33563',
'_ID': '0011'}
With the Python dict object, we can access each named-value pair, for example just the CITY:
Bristol
Preparing for writing to a new U2 file
Step 1: Get the Keys and the Values Step 2: Create the file
In [9]:
keys = mydict.keys()
values = mydict.values()
print(keys)
print(values)
dict_keys(['0011', '0384', '0757'])
dict_values([{'_ID': '0011', 'FIRST_NAME': 'Dwayne', 'LAST_NAME': 'Kennedy', 'CITY': 'Bristol', 'STATE': 'Idaho', 'ZIP': '33563'}, {'_ID': '0384', 'FIRST_NAME': 'Mitra', 'LAST_NAME': 'Bruce', 'CITY': 'St. Paul', 'STATE': 'Alaska', 'ZIP': '66340'}, {'_ID': '0757', 'FIRST_NAME': 'Steve', 'LAST_NAME': 'Seagle', 'CITY': 'Edmunston', 'STATE': 'West Virginia', 'ZIP': '51671'}])
Create the U2 file and dictionary ( Note this is a UniData example )
In [56]:
file_needed = 0
filename = "NEWMEMBERS"
try:
file = uopy.File(filename)
dfile = uopy.File(filename, uopy.DICT_FILE )
print("file opened")
except:
print("The file " + filename + " does not exist")
file_needed = 1
try:
if file_needed:
cmd = uopy.Command("CREATE.FILE " + filename + " 3 11")
cmd.run()
print("file created")
file = uopy.File("DATASOURCE")
dfile = uopy.File(filename, uopy.DICT_FILE )
print("now the file is opened")
except:
print("still an issue with the file")
print(type(file))
file opened <class 'uopy._file.File'>
Create U2 Dictionary items
Note this will step through the keys extracted in the last section and create d-type dictionary items.
In [57]:
one_obj = list(values)[0]
print(type(one_obj))
one_set_of_keys = one_obj.keys()
cnt = 0
for each_key in one_set_of_keys:
cnt += 1
print(each_key + " will be location " + str(cnt))
rec = [ "D", cnt, "", each_key, "10L", "S"]
dfile.write(each_key, rec)
cmd = uopy.Command("LIST DICT " + filename)
cmd.run()
print(cmd.response)
<class 'dict'> _ID will be location 1 FIRST_NAME will be location 2 LAST_NAME will be location 3 CITY will be location 4 STATE will be location 5 ZIP will be location 6 LIST DICT NEWMEMBERS BY TYP BY @ID TYP LOC CONV NAME FORMAT SM ASSOC 13:10:25 Nov 18 2021 1 @ID............ TYP LOC.......... CONV NAME........... FORMAT SM ASSOC..... @ID D 0 NEWMEMBERS 10L S CITY D 4 CITY 10L S FIRST_NAME D 2 FIRST_NAME 10L S LAST_NAME D 3 LAST_NAME 10L S STATE D 5 STATE 10L S ZIP D 6 ZIP 10L S _ID D 1 _ID 10L S 7 records listed
Now load the data
For this example, I am only loading the first object to the file
In [67]:
this_key = list(keys)[0]
the_fields = list(one_obj.keys())
the_values = [ list(one_obj.values()) ]
print(the_fields)
print(the_values)
st = file.write_named_fields(this_key, the_fields, the_values)
# Note 'ALL' is only in UniData
cmd = uopy.Command("LIST " + filename + " ALL")
cmd.run()
print(cmd.response)
['_ID', 'FIRST_NAME', 'LAST_NAME', 'CITY', 'STATE', 'ZIP'] [['0011', 'Dwayne', 'Kennedy', 'Bristol', 'Idaho', '33563']] LIST NEWMEMBERS ALL 13:21:45 Nov 18 2021 1 NEWMEMBERS _ID....... FIRST_NAME LAST_NAME. CITY...... STATE..... ZIP....... 0011 0011 Dwayne Kennedy Bristol Idaho 33563 1 record listed
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Mike Rajkowski
support
Rocket Internal - All Brands
DENVER CO US
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