When calling to custom api pythons thows error httplib.CannotSendHeader exception

Question

I made a simple script that performs POST http calls to an api by having it bode encoded as Json:

#!/usr/bin/python
# coding: utf-8

import sys
import httplib
from base64 import b64encode
from json import dumps

filename = sys.argv[1]
outfile = filename + ".txt"
with open(filename, 'rb') as f:
    content = f.read()

data = b64encode(content)

jsonData = {
    'param_1': 12,
    'param_2': 12,
    'filename': "45.jpg",
    'file_data': data
}

jsonData = dumps(jsonData)

headers = {
    "Content-Type": 'application/json',
    "Accept": '*/*'
}

conn = httplib.HTTPConnection('localhost',8016)
conn.putheader("Content-Type",'application/json')
conn.sendheaders()

conn.request('POST', '/files', jsonData, headers)

response = conn.getresponse()
print response

But I get the following error:

Traceback (most recent call last):
  File "./add_file.py", line 31, in <module>
    conn.putheader("Content-Type",'application/json')
  File "/usr/lib/python2.7/httplib.py", line 1026, in putheader
    raise CannotSendHeader()
httplib.CannotSendHeader

And I cannot figure out why. I tried to do anything I can think of but I fail.

Answer 1

Just remove the:

conn.putheader("Content-Type",'application/json')

Line from your code. By passing the headers object to the httplib.request method is just enough.