[Python-es] Expresiones regulares

Mie Jun 4 01:01:14 CEST 2014

Solucionado, dejo adjunto.

El 3 de junio de 2014, 19:56, Jhonatan Sneider Salguero Villa <
sney2002 en gmail.com> escribió:

> Hola,
>
> por lo que veo el json esta mal formado (o le falta una parte a la
> cadena), para poder parsearlo hay que eliminar la parte sobrante:
>
> import json
>
> # remover la parte sobrante
> json_string = json_string = string.replace(',"version":"1.0" ', '}')
>
> data = json.loads(json_string)
>
> # si la cadena tiene la misma estructura siempre puedes hacer esto
> channels = data["result"]["devices"][0]["channels"]
>
> key_value = map(lambda a: a.items(), channels)
>
> con esto tienes una lista de listas con el formato
>
> [('value', valor_value), ('meta', valor_meta), ('name', valor_name),
> ('unit', valor_unit)]
>
>
> El 3 de junio de 2014, 15:55, Miguel Angel Rodriguez <marodal en gmail.com>
> escribió:
>
> Este es un ejemplo de lo que recibo:
>>
>> {"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
>>
>> {"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
>>
>> Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"
>>
>> name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":"
>> "},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
>>
>>
>>
>> Quiero parsearlo para poder almacenar en unas variables que tengo los
>> values que aparecen en el JSON. De esta forma:
>>
>>  Con la solucion con expresiones regulares en cada iteracion tengo lo
>> siguiente:
>>  d_value = [name,(valor del name),unit,(valor del unit),meta,(valor del
>> meta),value,(valor del value)]
>>
>> En esa iteracion hago lo siguiente:
>> if d_value[1] == "PF":
>>     mi_variable_PF = d_value[7]
>> if d_value[1] == "Fac":
>>    mi_variable_Fac = d_value[7]
>> .....
>>
>> No necesito todos los values, solo los que corresponden a unos
>> determinados name.
>>
>> Con la solucion con expresiones regulares tengo el siguiente bug:
>> Alguna veces en el json aparece  "unit":"". Es decir, la clave key no
>> tiene valor, por lo que obtengo un array de solo 7 elementos (sin el
>> elemento valor del unit) y consigo recuperar el value para ese name.
>> ¿Alguien me podría ayudar con esto?
>>
>> Por ultimo, con la solucion con JSON, ¿es necesario usar ficheros? No se
>> como será el manejo de ficheros en el sistema donde va a funcionar este
>> python.
>>
>>
>> Gracias y un saludo
>>
>>
>> El 3 de junio de 2014, 22:53, Miguel Angel Rodriguez <marodal en gmail.com>
>> escribió:
>>
>> Este es un ejemplo de lo que recibo:
>>>
>>> {"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:
>>> 180340320","channels":[{"name":"PF","unit":"","meta":"PF","
>>> value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
>>>       {"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{
>>> "name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"
>>> name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
>>>       Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA"
>>> ,"meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","
>>> meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":""
>>> ,"meta":"ErrNoFirst","value":"0"},{"
>>> name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","
>>> value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-
>>> WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"
>>> Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":"
>>> "},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"
>>> name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"
>>> name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
>>>
>>>
>>>
>>> Quiero parsearlo para poder almacenar en unas variables que tengo los
>>> values que aparecen en el JSON. De esta forma:
>>>
>>>  Con la solucion con expresiones regulares en cada iteracion tengo lo
>>> siguiente:
>>>  d_value = [name,(valor del name),unit,(valor del unit),meta,(valor del
>>> meta),value,(valor del value)]
>>>
>>> En esa iteracion hago lo siguiente:
>>> if d_value[1] == "PF":
>>>     mi_variable_PF = d_value[7]
>>> if d_value[1] == "Fac":
>>>    mi_variable_Fac = d_value[7]
>>> .....
>>>
>>> No necesito todos los values, solo los que corresponden a unos
>>> determinados name.
>>>
>>> Con la solucion con expresiones regulares tengo el siguiente bug:
>>> Alguna veces en el json aparece  "unit":"". Es decir, la clave key no
>>> tiene valor, por lo que no consigo
>>>
>>>
>>> El 3 de junio de 2014, 22:40, Flavio Danesse <fdanesse en gmail.com>
>>> escribió:
>>>
>>> Si quieres pasame un string de ejemplo que esté completo y dime que
>>>> hacer con los values y te escribo la solución.
>>>>
>>>>
>>>> El 3 de junio de 2014, 17:38, Flavio Danesse <fdanesse en gmail.com>
>>>> escribió:
>>>>
>>>> Lo que hago es tomar el string que tienes y guardarlo en un archivo
>>>>> como texto plano pero luego lo cargo utilizando json con lo cual obtengo un
>>>>> diccionario python. Para obtener las keys y values del diccionario solo
>>>>> tienes que hacer diccionario.keys() y diccionario.values() o puedes hacer
>>>>> también diccionario.items() lo cual te da la pareja key:value.
>>>>>
>>>>> En todos los casos obtendrás lista de keys, values o items.
>>>>>
>>>>> Ahora bien, el primer obstáculo está salvado, que era pasar el string
>>>>> a un diccionario donde tienes parejas key-value.
>>>>>
>>>>> El segundo obstaculo es hacer recursividad dentro del diccionario para
>>>>> seguir hacia adentro de la estructura obteniendo los diccionarios internos.
>>>>> No es tan complicado, puedes comenzar con algo como:
>>>>>
>>>>> for key in diccionario.keys():
>>>>>     valor = diccionario[key]
>>>>>     . . .  lo que quieras con el key y lo que quieras con value aca
>>>>> importa que tipo de dato es el value, porque por lo que veo tienes listas,
>>>>> diccionarios, string, etc, utiliza type(valor) para operar sobre ellos
>>>>> según su tipo.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> El 3 de junio de 2014, 17:13, Miguel Angel Rodriguez <
>>>>> marodal en gmail.com> escribió:
>>>>>
>>>>> No entiendo que haces con archivo...
>>>>>>
>>>>>> Nunca he programado con json en python.
>>>>>>
>>>>>> ¿Como seria a partir de lo que indicas el parseo de los datos? Es
>>>>>> decir, ¿Como seria el bucle que me iria dando el name y el value?
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> 2014-06-03 22:08 GMT+02:00 Flavio Danesse <fdanesse en gmail.com>:
>>>>>>
>>>>>> Voto por lo correcto que sería así:
>>>>>>>
>>>>>>> import os
>>>>>>> import json
>>>>>>> import codecs
>>>>>>>
>>>>>>> text =
>>>>>>> '{"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320", etc
>>>>>>> . . .
>>>>>>>
>>>>>>> path = "/tmp/x.json"
>>>>>>>
>>>>>>> archivo = open(path, "w")
>>>>>>> archivo.write(text)
>>>>>>> archivo.close()
>>>>>>>
>>>>>>> archivo = codecs.open(path, "r", "utf-8")
>>>>>>> diccionario = json.JSONDecoder("utf-8").decode(archivo.read())
>>>>>>>
>>>>>>>
>>>>>>> El 3 de junio de 2014, 8:03, <gustavo en nodo50.org> escribió:
>>>>>>>
>>>>>>> ejecutando esto:
>>>>>>>>
>>>>>>>> #!/usr/bin/python3
>>>>>>>> import re
>>>>>>>> value_str =
>>>>>>>>
>>>>>>>> '{"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},{"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kVAr","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":""},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>>>>>>>>
>>>>>>>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"'
>>>>>>>>
>>>>>>>> for channel_str in
>>>>>>>> re.findall("\"name\":\"[A-Za-z0-9\-.]+\"",value_str):
>>>>>>>>  for channel_str1 in
>>>>>>>> re.findall("\"value\":\"[A-Za-z0-9\-.]+\"",value_str):
>>>>>>>>   print ( channel_str + ";" + channel_str1 )
>>>>>>>>
>>>>>>>> me da esto:
>>>>>>>>
>>>>>>>> "name":"Cntry";"value":"335.2"
>>>>>>>> "name":"Cntry";"value":"-1.0"
>>>>>>>> "name":"Cntry";"value":"335.1"
>>>>>>>> "name":"Cntry";"value":"49.950"
>>>>>>>> "name":"Cntry";"value":"0"
>>>>>>>> "name":"Cntry";"value":"Off"
>>>>>>>> "name":"Cntry";"value":"Off"
>>>>>>>> "name":"Cntry";"value":"---"
>>>>>>>> "name":"Cntry";"value":"DE1"
>>>>>>>> "name":"Cntry";"value":"SCG"
>>>>>>>> "name":"Cntry";"value":"Operation"
>>>>>>>> "name":"Cntry";"value":"---"
>>>>>>>> "name":"Type";"value":"1.000"
>>>>>>>> "name":"Type";"value":"935"
>>>>>>>> "name":"Type";"value":"217.5"
>>>>>>>> "name":"Type";"value":"513.8"
>>>>>>>> "name":"Type";"value":"335.2"
>>>>>>>> "name":"Type";"value":"-1.0"
>>>>>>>> "name":"Type";"value":"335.1"
>>>>>>>> "name":"Type";"value":"49.950"
>>>>>>>>
>>>>>>>>
>>>>>>>> te vale?
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> > Hola a todos,
>>>>>>>> >
>>>>>>>> > Estoy intentando parsear con Python una gran cadena que recibo en
>>>>>>>> un
>>>>>>>> > software de comunicaciones que estoy programando.
>>>>>>>> >
>>>>>>>> > La cadena que yo recibo es la siguiente:
>>>>>>>> >
>>>>>>>> > value_str =
>>>>>>>> >
>>>>>>>> {"format":"JSON","result":{"devices":[{"key":"SCGDE1BA:180340320","channels":[{"name":"PF","unit":"","meta":"PF","value":"1.000"},{"name":"P-WSpt","unit":"kW","meta":"P-WSpt","value":"935"},
>>>>>>>> >
>>>>>>>> >
>>>>>>>> {"name":"Vac","unit":"V","meta":"Vac","value":"217.5"},{"name":"Iac","unit":"A","meta":"Iac","value":"513.8"},{"name":"Pac","unit":"kW","meta":"Pac","value":"335.2"},{"name":"Qac","unit":"kV
>>>>>>>> >
>>>>>>>> >
>>>>>>>> Ar","meta":"Qac","value":"-1.0"},{"name":"Sac","unit":"kVA","meta":"Sac","value":"335.1"},{"name":"Fac","unit":"Hz","meta":"Fac","value":"49.950"},{"name":"ErrNoFirst","unit":"","meta":"ErrNoFirst","value":"0"},{"
>>>>>>>> >
>>>>>>>> >
>>>>>>>> name":"P-WModFailStt","unit":"","meta":"P-WModFailStt","value":"Off"},{"name":"P-WModStt","unit":"","meta":"P-WModStt","value":"Off"},{"name":"Dsc","unit":"","meta":"Dsc","value":"---"},{"name":"Firmware-9","unit":"","meta":"Firmware-9","value":"
>>>>>>>> > "},{"name":"Cntry","unit":"","meta":"Cntry","value":"DE1"}
>>>>>>>> >
>>>>>>>> ,{"name":"Type","unit":"","meta":"Type","value":"SCG"},{"name":"Mode","unit":"","meta":"Mode","value":"Operation"},{"name":"Error","unit":"","meta":"Error","value":"---"}]}]},"version":"1.0"
>>>>>>>> >
>>>>>>>> >
>>>>>>>> > Yo solo quiero quedarme con los name y value existente.
>>>>>>>> >
>>>>>>>> > LA forma en la que lo estoy intentando es la siguiente:
>>>>>>>> >
>>>>>>>> > for channel_str in re.findall("\"name\":\"[A-Za-z0-9\-.
>>>>>>>> > ]+\",\"value\":\"[A-Za-z0-9\-. ]*\"",value_str):
>>>>>>>> >             d_value = re.findall("[A-Za-z0-9.\-]+",channel_str)
>>>>>>>> >
>>>>>>>> > Pero de esta forma no entra en el for.
>>>>>>>> >
>>>>>>>> > ¿Alguien me puede ayudar?
>>>>>>>> >
>>>>>>>> > Gracias y un saludo
>>>>>>>> >
>>>>>>>> >
>>>>>>>> >
>>>>>>>> >
>>>>>>>> >
>>>>>>>> >
>>>>>>>> > --
>>>>>>>> > Miguel Ángel Rodríguez de Alba
>>>>>>>> > 678304435
>>>>>>>> > marodal en gmail.com
>>>>>>>> > _______________________________________________
>>>>>>>> > Python-es mailing list
>>>>>>>> > Python-es en python.org
>>>>>>>> > https://mail.python.org/mailman/listinfo/python-es
>>>>>>>> > FAQ: http://python-es-faq.wikidot.com/
>>>>>>>> >
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Python-es mailing list
>>>>>>>> Python-es en python.org
>>>>>>>> https://mail.python.org/mailman/listinfo/python-es
>>>>>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Python-es mailing list
>>>>>>> Python-es en python.org
>>>>>>> https://mail.python.org/mailman/listinfo/python-es
>>>>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Miguel Ángel Rodríguez de Alba
>>>>>> 678304435
>>>>>> marodal en gmail.com
>>>>>>
>>>>>> _______________________________________________
>>>>>> Python-es mailing list
>>>>>> Python-es en python.org
>>>>>> https://mail.python.org/mailman/listinfo/python-es
>>>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>>>
>>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> Python-es mailing list
>>>> Python-es en python.org
>>>> https://mail.python.org/mailman/listinfo/python-es
>>>> FAQ: http://python-es-faq.wikidot.com/
>>>>
>>>>
>>>
>>>
>>> --
>>> Miguel Ángel Rodríguez de Alba
>>> 678304435
>>> marodal en gmail.com
>>>
>>
>>
>>
>> --
>> Miguel Ángel Rodríguez de Alba
>> 678304435
>> marodal en gmail.com
>>
>> _______________________________________________
>> Python-es mailing list
>> Python-es en python.org
>> https://mail.python.org/mailman/listinfo/python-es
>> FAQ: http://python-es-faq.wikidot.com/
>>
>>
>
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> Python-es mailing list
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> https://mail.python.org/mailman/listinfo/python-es
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>
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