Multipart form post, csv and param python - python-3.x

Question

Im having difficulty with the following code:
payload = {
'file' : ('csvtest.csv', open('csvtest.csv', 'rb')),
'parser' : '{"name":"CSV","displayName":null,"description":"Supports delimited text files with a field delimiter and optional escape and quote characters.","shortDescription":null,"properties":[{"name":"Auto Detect?","displayName":"Auto Detect?","value":"true","values":null,"placeholder":"","type":"select","hint":"Auto detect will attempt to infer delimiter from the sample file.","objectProperty":"autoDetect","selectableValues":[{"label":"true","value":"true","hint":null},{"label":"false","value":"false","hint":null}],"required":false,"group":"","groupOrder":1,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_0"},{"name":"Header?","displayName":"Header?","value":"true","values":null,"placeholder":"","type":"select","hint":"Whether file has a header.","objectProperty":"headerRow","selectableValues":[{"label":"true","value":"true","hint":null},{"label":"false","value":"false","hint":null}],"required":false,"group":"","groupOrder":2,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_1"},{"name":"Delimiter Char","displayName":"Delimiter Char","value":",","values":null,"placeholder":"","type":"string","hint":"Character separating fields","objectProperty":"separatorChar","selectableValues":[],"required":false,"group":"","groupOrder":3,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_2"},{"name":"Quote Char","displayName":"Quote Char","value":"\'","values":null,"placeholder":"","type":"string","hint":"Character enclosing a quoted string","objectProperty":"quoteChar","selectableValues":[],"required":false,"group":"","groupOrder":4,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_3"},{"name":"Escape Char","displayName":"Escape Char","value":"\\\\","values":null,"placeholder":"","type":"string","hint":"Escape character","objectProperty":"escapeChar","selectableValues":[],"required":false,"group":"","groupOrder":5,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_4"}],"objectClassType":"com.thinkbiganalytics.discovery.parsers.csv.CSVFileSchemaParser","objectShortClassType":"CSVFileSchemaParser","propertyValuesDisplayString":null,"supportsBinary":false,"generatesHiveSerde":true,"tags":["CSV","TSV"],"clientHelper":null,"allowSkipHeader":true,"groups":[{"group":"","layout":"column","properties":[{"name":"Auto Detect?","displayName":"Auto Detect?","value":"true","values":null,"placeholder":"","type":"select","hint":"Auto detect will attempt to infer delimiter from the sample file.","objectProperty":"autoDetect","selectableValues":[{"label":"true","value":"true","hint":null},{"label":"false","value":"false","hint":null}],"required":false,"group":"","groupOrder":1,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_0"},{"name":"Header?","displayName":"Header?","value":"true","values":null,"placeholder":"","type":"select","hint":"Whether file has a header.","objectProperty":"headerRow","selectableValues":[{"label":"true","value":"true","hint":null},{"label":"false","value":"false","hint":null}],"required":false,"group":"","groupOrder":2,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_1"},{"name":"Delimiter Char","displayName":"Delimiter Char","value":",","values":null,"placeholder":"","type":"string","hint":"Character separating fields","objectProperty":"separatorChar","selectableValues":[],"required":false,"group":"","groupOrder":3,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_2"},{"name":"Quote Char","displayName":"Quote Char","value":"\'","values":null,"placeholder":"","type":"string","hint":"Character enclosing a quoted string","objectProperty":"quoteChar","selectableValues":[],"required":false,"group":"","groupOrder":4,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_3"},{"name":"Escape Char","displayName":"Escape Char","value":"\\\\","values":null,"placeholder":"","type":"string","hint":"Escape character","objectProperty":"escapeChar","selectableValues":[],"required":false,"group":"","groupOrder":5,"layout":"column","hidden":false,"pattern":"","patternInvalidMessage":"Invalid Input","formKey":"property_4"}]}],"editable":true}'
}
headers = {
'accept': "application/json",
'authorization': "Basic ZGxhZG1pbjp0aGlua2JpZw==",
'cache-control': "no-cache",
}
url = "http://localhost:8400/proxy/v1/schema-discovery/hive/sample-file"
req = requests.post(url, data=payload, headers=headers)
print(req.text)
For some reason im getting the error "HTTP 415 Unsupported Media Type".
I'm trying to send a csv, along with some json in a multipart form. I originally had this working with http.client but the way I was doing it it was adding extra line breaks and carriage return literals into the multipart message body.
Any help greatly appreciated!

Answer 1

The issue I couldnt originally see was with declaring the file type in the file tuple, shown below as 'text/csv' in the solution.
import http.client
file = { 'file' : ('csvtest.csv', open('csvtest.csv', 'rt'), 'text/csv') }
payload = { 'parser' : '{object trimmed for comment}' }
headers = { 'accept': "application/json", 'authorization': "Basic ZGxhZG1pbjp0aGlua2JpZw==", }
url = "http://localhost:8400/proxy/v1/schema-discovery/hive/sample‌​-file"
req = requests.post(url, data=payload, files=file, headers=headers)
pprint(req.text)