util: add utility functions

Author: Samiul Sk

imagekitio/utils/__init__.py

@@ -0,0 +1,39 @@
+import hashlib
+import hmac
+import uuid
+from datetime import datetime as dt
+
+from imagekitio.constants import ERRORS
+
+DEFAULT_TIME_DIFF = 60 * 30
+
+
+def hamming_distance(first: str, second: str) -> int:
+    """Calculate Hamming Distance between to hex string
+    """
+    try:
+        a = bin(int(first, 16))[2:].zfill(64)
+        b = bin(int(second, 16))[2:].zfill(64)
+    except TypeError:
+        raise TypeError(ERRORS.INVALID_PHASH_VALUE.value)
+
+    return len(list(filter(lambda x: ord(x[0]) ^ ord(x[1]), zip(a, b))))
+
+
+def get_authenticated_params(token, expire, private_key):
+    default_expire = int(dt.now().strftime("%s")) + DEFAULT_TIME_DIFF
+    auth_params = {"token": token, "expire": expire, "signature": ""}
+
+    if not private_key:
+        return
+    signature = hmac.new(
+        key=private_key.encode(),
+        msg=(token + str(expire)).encode(),
+        digestmod=hashlib.sha1,
+    ).hexdigest()
+
+    auth_params["token"] = token or str(uuid.uuid4())
+    auth_params["expire"] = expire or default_expire
+    auth_params["signature"] = signature
+
+    return auth_params

imagekitio/utils/calculation.py

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+import re
+from collections import ChainMap, OrderedDict
+from typing import Dict, List
+
+
+def camel_to_snake(name):
+    """
+    converts camelCase to snake_case for python
+    """
+    s1 = re.sub("(.)([A-Z][a-z]+)", r"\1_\2", name)
+    return re.sub("([a-z0-9])([A-Z])", r"\1_\2", s1).lower()
+
+
+def snake_to_lower_camel(word):
+    """
+    changes word snake to  lower camelCase example: my_plan -> MyPlan
+    :return camelCaseWord
+    """
+    word_list = word.split("_")
+    if word_list:
+        return word_list[0] + "".join(x.title() for x in word_list[1:])
+    return word
+
+
+def request_formatter(data: dict) -> dict:
+    """Converts all keys to camelCase format required for ImageKit server
+    :param data: dict()
+    :return: converted_dict -> dict()
+    """
+    return {snake_to_lower_camel(key): val for key, val in data.items()}
+
+
+def camel_dict_to_snake_dict(data: dict) -> dict:
+    return {camel_to_snake(key): val for key, val in data.items()}
+
+
+def flatten_dict(dict_list: List[Dict]) -> OrderedDict:
+    """Convert list of dictionary to flatten dict
+    :param dict_list: list of dictionary
+    :return: flatten_dict
+    """
+    flat_dict = OrderedDict()
+    for dict_var in dict_list:
+        flat_dict.update(dict_var)
+    return flat_dict