Quoting from the docs

data – (optional) Dictionary or bytes to send in the body of the Request.

So this should work (not tested):

 filepath = 'yourfilename.txt'
 with open(filepath) as fh:
     mydata = fh.read()
     response = requests.put('https://api.elasticemail.com/attachments/upload',
                data=mydata,                         
                auth=('omer', 'b01ad0ce'),
                headers={'content-type':'text/plain'},
                params={'file': filepath}
                 )

Even after three attempts to clarify the question, it still isn't clear what you're asking here, but I can try to throw out enough info that you can figure out the answer.

First, r = requests.put(url, data = string) returns a Response, which doesn't have a body, but it does have a request, and a history of 0 or more redirect requests, all of which are PreparedRequest objects, which do have body attributes.

On the other hand, if you did r.requests.Request(method='PUT', url=url, data=string), that would return a Request, which has to be prepare()d before it has a body.

Either way, if I do a simple test and look at the results, I find that the body is always correct:

Copy>>> resp = requests.put('http://localhost/nosuchurl', data='abc')
>>> resp.request.body
'abc'
>>> resp = requests.put('http://localhost/redirect_to_https', data='abc')
>>> resp.history[-1].request.body
'abc'
>>> req = requests.Request(method='PUT', url='http://localhost/nosuchurl', data='abc')
>>> preq = req.prepare()
>>> preq.body
'abc'

My best guess is that you need to be looking at resp.history[0].request.body, but you're looking at resp.request.body, or something similar.

If Redirection and History in the quickstart tutorial doesn't help, read the detailed API docs, or just experiment with all of them until you figure it out.

Or do this:

Copyresp = request.put('http://localhost/nosuchurl', data='abc', allow_redirects=False)

And then do the redirect-handling manually.

It seams this page expects data as JSON so you need

page = session.post(url, json=data)

BTW:

Server always assigns new cookies to new client - especially cookie line ASP.NET_SessionId - so better GET main page to get new cookies before you do other requests.

After session.headers.update(headers) you don't have to use headers=headers in get()/post(). You may have to only change some headres if some request need some extra header.

If you use json= then it automatically add header "Content-Type": "application/json;charset=utf-8"

Full code could look like this:

import requests

# -- create session ---

session = requests.session()

headers = {
    "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0",
    "Accept": "application/json, text/plain, */*",
    "Accept-Language": "en-US,en;q=0.5",
    "Connection": "keep-alive"
}

# set headers for all requests
session.headers.update(headers)

# --- get cookies ---

url = "https://www.pocruises.com.au/"
page = session.get(url)

# --- search ---

data = {
    "searchParameters": {
        "p": [],
        "c": [],
        "d": [],
        "s": [],
        "ms": [],
        "adv": [],
        "sort": "dpa",
        "page": 5
    },
    "renderingParameters": {
        "DefaultSortOption": "dpa",
        "LargeScreenFlag": "true",
        "NewModelIsLoading": "false",
        "PagingAnchor": "",
        "ViewStyleSelectorVisible": "true",
        "FilterBarVisible": "true",
        "NumberOfResultsAndSortByPanelVisible": "true",
        "DefaultResultsView": "Grid",
        "MaxNumberOfResults": 0,
        "PaginationEnabled": "true",
        "KeepPageState": "true",
        "PageSize": 9,
        "DefaultResultsGrouping": "Itinerary",
        "Duration": [],
        "CruiseItinerary": [],
        "Voyage": [],
        "ExcludeVoyage": [],
        "PromoCode": [],
        "AdditionalPromoCodes": []
    }
}

url = "https://www.pocruises.com.au/sc_ignore/b2c/cruiseresults/searchresults"

# `json=` add `"Content-Type": "application/json;charset=utf-8"`

page = session.post(url, json=data)

print(page.text)
cruise_data = page.json()
print(cruise_data)

Your data is already a JSON-formatted string. You can pass it directly to requests.put instead of converting it with json.dumps again.

Change:

response = requests.put(url, data=json.dumps(data), headers=headers)

to:

response = requests.put(url, data=data, headers=headers)

Alternatively, your data can store a data structure instead, so that json.dumps can convert it to JSON.

Change:

data = '[{"$key": 8},{"$key": 7}]'

to:

data = [{"$key": 8},{"$key": 7}]

I've used a variety of python HTTP libs in the past, and I've settled on requests as my favourite. Existing libs had pretty useable interfaces, but code can end up being a few lines too long for simple operations. A basic PUT in requests looks like:

payload = {'username': 'bob', 'email': '[email protected]'}
>>> r = requests.put("http://somedomain.org/endpoint", data=payload)

You can then check the response status code with:

r.status_code

or the response with:

r.content

Requests has a lot synactic sugar and shortcuts that'll make your life easier.