rename built-in file name

ate/built_in.py

@@ -0,0 +1,30 @@
+"""
+Built-in dependent functions used in YAML/JSON testcases.
+"""
+
+import datetime
+import random
+import string
+import time
+
+from ate.exception import ParamsError
+
+
+def gen_random_string(str_len):
+    """ generate random string with specified length
+    """
+    return ''.join(
+        random.choice(string.ascii_letters + string.digits) for _ in range(str_len))
+
+def get_timestamp(str_len=13):
+    """ get timestamp string, length can only between 0 and 16
+    """
+    if isinstance(str_len, int) and 0 < str_len < 17:
+        return str(time.time()).replace(".", "")[:str_len]
+
+    raise ParamsError("timestamp length can only between 0 and 16.")
+
+def get_current_date(fmt="%Y-%m-%d"):
+    """ get current date, default format is %Y-%m-%d
+    """
+    return datetime.datetime.now().strftime(fmt)