Coverts a standard Python dictionary to a Boto3 DynamoDB item

dict_to_dynamodb_item.py

def dict_to_item(raw):
    if type(raw) is dict:
        resp = {}
        for k,v in raw.iteritems():
            if type(v) is str:
                resp[k] = {
                    'S': v
                }
            elif type(v) is int:
                resp[k] = {
                    'I': str(v)
                }
            elif type(v) is dict:
                resp[k] = {
                    'M': dict_to_item(v)
                }
            elif type(v) is list:
                resp[k] = []
                for i in v:
                    resp[k].append(dict_to_item(i))
                    
        return resp
    elif type(raw) is str:
        return {
            'S': raw
        }
    elif type(raw) is int:
        return {
            'I': str(raw)
        }

Very helpful, thanks!

Thank you!

Very helpful, thanks!

Thank you for adding time back to my life!!

How about:

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
            'M': {
                k: dict_to_item(v)
                for k, v in raw.items()
            }
        }
    elif isinstance(raw, list):
        return {
            'L': [dict_to_item(v) for v in raw]
        }
    elif isinstance(raw, str):
        return {'S': raw}
    elif isinstance(raw, int):
        return {'N': str(raw)}

@odedniv ; much better. the original gist was on the write track, but was missing a few edge cases.

@odedniv thanks

Well, i had some errors with the second code, so i had to make some minor tweaks..

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
            'M': {
                key: dict_to_item(value)
                for key, value in raw.items()
            }
        }
    elif isinstance(raw, list):
        return {
            'L': [dict_to_item(value) for value in raw]
        }
    elif isinstance(raw, str) or isinstance(raw, unicode):
        return {'S': raw}
    elif isinstance(raw, int):
        return {'N': str(raw)}
    elif raw is None:
        return {'NULL': True}

Improved the above code

1. isintance accepts tuple to use in or conditions
2. Handled float, bool, bytes types

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
            'M': {
                key: dict_to_item(value)
                for key, value in raw.items()
            }
        }
    elif isinstance(raw, list):
        return {
            'L': [dict_to_item(value) for value in raw]
        }
    elif isinstance(raw, (str, unicode)):
        return {'S': raw}
    elif isinstance(raw, (int, float)):
        return {'N': str(raw)}
    elif isinstance(raw, bool):
        return {'BOOL': raw}
    elif isinstance(raw, bytes):
        return {'B': raw}
    elif raw is None:
        return {'NULL': True}

When checking with isinstance() we should take care for the sequence. First check for 'bool' and only then for 'int' and 'float'
because isinstance(raw, (int, float)) returns True for boolen values:

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
            'M': {
                key: dict_to_item(value)
                for key, value in raw.items()
            }
        }
    elif isinstance(raw, list):
        return {
            'L': [dict_to_item(value) for value in raw]
        }
    elif isinstance(raw, (str, unicode)):
        return {'S': raw}
    elif isinstance(raw, bool):
        return {'BOOL', raw}
    elif isinstance(raw, (int, float)):
        return {'N': str(raw)}
    elif isinstance(raw, bytes):
        return {'B', raw}
    elif raw is None:
        return {'NULL': True}

@akshowhini
Can you edit your post. for bool, you have a comma instead of a colan.
But thanks all, i was thinking of how to covert my dict to dynamoDB and didnt want to have to write this :)

Thanks, I wasn't able to insert the values in this format:

boto3.version : '1.12.43'
Python 3.6.10 |Anaconda, Inc.| (default, Mar 23 2020, 17:58:33) [MSC v.1916 64 bit (AMD64)] on win32

{'M': {'Row No': {'S': '1'},
 'Activity': {'S': 'Playing'},
 'Game \n Indoor': {'S': 'Football'},
 'TIME_STAMP': {'S': '20200426-155655-8555'},
 'ID': {'S': '5305968026208007210'}
}}

or

{'Row No': {'S': '1'},
 'Activity': {'S': 'Playing'},
 'Game \n Indoor': {'S': 'Football'},
 'TIME_STAMP': {'S': '20200426-155655-8555'},
 'ID': {'S': '5305968026208007210'}
}

So I made another tweak to get the work done

#To Correct The Keys, If Automated Extraction From Forms
def get_corrected_key(key):
    removal_list = [' ', '\t', '\n']
    for s in removal_list:
        key = key.replace(s, '')
    return key

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
                get_corrected_key(key): dict_to_item(value)
                for key, value in raw.items()
        }
    elif isinstance(raw, list):
        return {
            [dict_to_item(value) for value in raw]
        }
    elif isinstance(raw, str):
        # Empty Strings are not a valid entry 
        if len(raw) ==0:
            return '-'
        return raw
    elif isinstance(raw, bool):
        return raw
    elif isinstance(raw, (int, float)):
        return str(raw)
    elif isinstance(raw, bytes):
        return raw
    elif raw is None:
        return True

table_work.put_item(
    Item=dict_to_item(item))

I wanted to use this with a pandas DataFrame object so I used it like this:

import pandas as pd

def preprocess_df(df):
    df.index = df.index.astype('str')
    df_dict = df.to_dict()
    return df_dict

def dict_to_item(raw):
    if isinstance(raw, dict):
        return {
            'M': {
                key: dict_to_item(value)
                for key, value in raw.items()
            }
        }
    elif isinstance(raw, list):
        return {
            'L': [dict_to_item(value) for value in raw]
        }
    elif isinstance(raw, (str)):
        return {'S': raw}
    elif isinstance(raw, bool):
        return {'BOOL': raw}
    elif isinstance(raw, (int, float)):
        return {'N': str(raw)}
    elif isinstance(raw, bytes):
        return {'B', raw}
    elif raw is None:
        return {'NULL': True}

def df_to_aws_dict(df):
    aws_dict = dict_to_item(preprocess_df(df))
    return aws_dict

from boto3.dynamodb.types import TypeSerializer
serializer = TypeSerializer()
item = {"foo": "bar"}
dyn_item = {key: serializer.serialize(value) for key, value in item.items()}

from boto3.dynamodb.types import TypeSerializer
serializer = TypeSerializer()
item = {"foo": "bar"}
dyn_item = {key: serializer.serialize(value) for key, value in item.items()}

This really works for me. Thanks a lot, @yousefcodes . I was Stack on it for 1 day. Much Appreciated. Is it possible to do as this works in Update items?