Edit Json schema with python -

i have main json-schema. looks that:

{   "$schema": "http://json-schema.org/draft-04/schema#",   "type": "object",   "properties": {     "listinfo": {       "type": "object",       "properties": {         "limit": {           "type": "integer"         },         "count": {           "type": "integer"         }       },       "required": [         "offset",         "count"       ]     },     "items": {       "type": ["array", "null"],       "items": {         "type": "object",         "properties": {           "startdate": {             "type": "string"           },           "customer": {             "type": "object",             "properties": {               "customerid": {                 "type": "integer"               },               "name": {                 "type": "string"               }             },             "required": [               "customerid",               "name"             ]           }         },         "required": [           "startdate",           "customer"         ]       }     }   },   "required": [     "listinfo",     "items"   ] } 

every time after sending query host check json on validation schema. need not fields in it. example can add "&fields=startdate" in end of query. how can generate new json schema new data (i need automatically delete lines "customer" in old json schema , generate new json-schema file)?