remove isodate dependency

setup.cfg

@@ -21,7 +21,6 @@ install_requires =
   PyYAML>=6.0
   Jinja2>=3.1.2
   click>=8.0
-  isodate>=0.6.1
 tests_require =
   pytest
   flake8

src/jcb/__init__.py

@@ -14,7 +14,7 @@
 from .observation_chronicle.satellite_chronicle import process_satellite_chronicles
 from .renderer import render as render
 from .renderer import Renderer as Renderer
-from .utilities.config_parsing import datetime_from_conf
+from .utilities.config_parsing import datetime_from_conf, duration_from_conf
 from .utilities.parse_channels import parse_channels, parse_channels_set
 from .utilities.trapping import abort, abort_if
 
@@ -25,6 +25,7 @@
     'ObservationChronicle',
     'process_satellite_chronicles',
     'datetime_from_conf',
+    'duration_from_conf',
     'parse_channels',
     'parse_channels_set',
     'abort_if',

src/jcb/observation_chronicle/observation_chronicle.py

@@ -4,7 +4,6 @@
 from datetime import datetime
 import os
 
-import isodate
 import jcb
 import yaml
 
@@ -25,7 +24,7 @@ def __init__(self, chronicle_path, window_begin, window_length):
         self.window_begin = datetime.strptime(window_begin, '%Y-%m-%dT%H:%M:%SZ')
 
         # Add window_length to window_begin
-        self.window_final = self.window_begin + isodate.parse_duration(window_length)
+        self.window_final = self.window_begin + jcb.duration_from_conf(window_length)
 
         # Save the most recent observer that was passed to the class. This can be used to avoid
         # re-precessing the chronicles if the same observer is used multiple times.

src/jcb/renderer.py

@@ -206,7 +206,7 @@ def render(self, algorithm):
             # Pointer to observers (mutable list so should not copy here)
             observers_dict = get_nested_dict(jedi_dict, observer_location)
 
-            # Loop over the observers and remove the non allowably components
+            # Loop over the observers and remove the non allowable components
             for observer_dict in observers_dict:
                 for key in observer_dict:
                     # Remove key if not in the observer components

src/jcb/utilities/config_parsing.py

@@ -1,7 +1,7 @@
 # --------------------------------------------------------------------------------------------------
 
 
-from datetime import datetime
+from datetime import datetime, timedelta
 import re
 
 import jcb
@@ -46,3 +46,87 @@ def datetime_from_conf(datetime_input):
 
 
 # --------------------------------------------------------------------------------------------------
+
+
+def check_duration_ordered(iso_duration):
+
+    """
+    Check if iso_duration characters is in correct order. The function will return True if the \
+    characters in the iso_duration are in the correct order. The function is case sensitive.
+
+    Args:
+        iso_duration (str): The iso_duration characters to check.
+
+    Returns:
+        bool: True if the iso_duration is in correct order, False otherwise.
+    """
+
+    # Reference string for the correct order of the characters
+    reference = "PYMWDTHMS"
+
+    # Strip non alpha characters from the string
+    iso_duration_letters = re.sub('[^a-zA-Z]', '', iso_duration)
+
+    # Check that letters in the ios duration string are in the correct order
+    search_start = 0
+    for char in iso_duration_letters:
+        # Try to find the current character in the reference string, starting from search_start
+        found_pos = reference.find(char, search_start)
+        if found_pos == -1:
+            # Character not found in the reference string, order is not preserved
+            return False
+        else:
+            # Move search_start to the position after the found character
+            search_start = found_pos + 1
+    # All characters found in order, return True
+    return True
+
+
+# --------------------------------------------------------------------------------------------------
+
+
+def duration_from_conf(iso_duration_input):
+
+    """
+    Convert an ISO 8601 duration string to a timedelta object. The string must be at least 2
+    characters long to be a valid duration string.
+
+    Args:
+        iso_duration_input (str or timedelta object): The ISO duration string to convert.
+
+    Returns:
+        timedelta: The timedelta object.
+    """
+
+    # If the input is already a timedelta object then return it
+    if isinstance(iso_duration_input, timedelta):
+        return iso_duration_input
+
+    # If not a string then abort
+    jcb.abort_if(not isinstance(iso_duration_input, str),
+                 f"The ISO duration \'{iso_duration_input}\' is not a string.")
+
+    # Strip non alpha characters from the string
+    jcb.abort_if(len(iso_duration_input) < 2,
+                 f"The ISO duration \'{iso_duration_input}\' must be at least 2 characters long.")
+
+    # Format is P[n]Y[n]M[n]W[n]DT[n]H[n]M[n]S. Use regex to extract the values
+    pattern = r'P(?:(\d+)Y)?(?:(\d+)M)?(?:(\d+)W)?(?:(\d+)D)?T?(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?'
+    pattern_compile = re.compile(pattern)
+    years, months, weeks, days, hours, minutes, seconds = \
+        pattern_compile.match(iso_duration_input).groups()
+
+    # Assert that years and months are None
+    jcb.abort_if(years is not None or months is not None,
+                 f"The ISO duration \'{iso_duration_input}\' must not have years or months. This "
+                 "is not supported by the timedelta class in the Python standard.")
+
+    # Create the timedelta object
+    return timedelta(weeks=int(weeks or 0),
+                     days=int(days or 0),
+                     hours=int(hours or 0),
+                     minutes=int(minutes or 0),
+                     seconds=int(seconds or 0))
+
+
+# --------------------------------------------------------------------------------------------------