Python standard library to POST multipart/form-data encoded data
The standard library does not currently support that. There is cookbook recipe that includes a fairly short piece of code that you just may want to copy, though, along with long discussions of alternatives.
It's an old thread but still a popular one, so here is my contribution using only standard modules.
The idea is the same than here but support Python 2.x and Python 3.x.It also has a body generator to avoid unnecessarily memory usage.
import codecsimport mimetypesimport sysimport uuidtry: import ioexcept ImportError: pass # io is requiered in python3 but not available in python2class MultipartFormdataEncoder(object): def __init__(self): self.boundary = uuid.uuid4().hex self.content_type = 'multipart/form-data; boundary={}'.format(self.boundary) @classmethod def u(cls, s): if sys.hexversion < 0x03000000 and isinstance(s, str): s = s.decode('utf-8') if sys.hexversion >= 0x03000000 and isinstance(s, bytes): s = s.decode('utf-8') return s def iter(self, fields, files): """ fields is a sequence of (name, value) elements for regular form fields. files is a sequence of (name, filename, file-type) elements for data to be uploaded as files Yield body's chunk as bytes """ encoder = codecs.getencoder('utf-8') for (key, value) in fields: key = self.u(key) yield encoder('--{}\r\n'.format(self.boundary)) yield encoder(self.u('Content-Disposition: form-data; name="{}"\r\n').format(key)) yield encoder('\r\n') if isinstance(value, int) or isinstance(value, float): value = str(value) yield encoder(self.u(value)) yield encoder('\r\n') for (key, filename, fd) in files: key = self.u(key) filename = self.u(filename) yield encoder('--{}\r\n'.format(self.boundary)) yield encoder(self.u('Content-Disposition: form-data; name="{}"; filename="{}"\r\n').format(key, filename)) yield encoder('Content-Type: {}\r\n'.format(mimetypes.guess_type(filename)[0] or 'application/octet-stream')) yield encoder('\r\n') with fd: buff = fd.read() yield (buff, len(buff)) yield encoder('\r\n') yield encoder('--{}--\r\n'.format(self.boundary)) def encode(self, fields, files): body = io.BytesIO() for chunk, chunk_len in self.iter(fields, files): body.write(chunk) return self.content_type, body.getvalue()Demo
# some utf8 key/value pairsfields = [('প্রায়', 42), ('bar', b'23'), ('foo', 'ން:')]files = [('myfile', 'image.jpg', open('image.jpg', 'rb'))]# iterate and write chunk in a socketcontent_type, body = MultipartFormdataEncoder().encode(fields, files)