Flask Post returning error

[subhabrata.banerji at gmail.com]

Dear Group,

I am trying to practice Flask and trying to correspond with it with through requests. 

I am being able to DELETE, GET. But as I am doing POST it is not posting the data rather returning null. 

I tried to search Flask and requests tutorials but did not get much. 
I am newly practising Flask, and on Python2.7+ with Windows 7 Professional. 

>>> var1=requests.get('http://127.0.0.1:5000/todos')
>>> var2=var2.text
>>> print var3
{
    "todo1": {
        "task": "build an API"
    }, 
    "todo2": {
        "task": "How are you?"
    }, 
    "todo3": {
        "task": "profit!"
    }
}
>>> import json
>>> payload = {'key1': 'value1'}
>>> var4=requests.post('http://127.0.0.1:5000/todos', data=json.dumps(payload))
>>> var5=requests.get('http://127.0.0.1:5000/todos')
>>> var6=var5.text
>>> print var6
{
    "todo1": {
        "task": "build an API"
    }, 
    "todo3": {
        "task": null
    }
}

If anyone may kindly suggest what is the error I am doing. 

Regards,
Subhabrata Banerjee.