feat: add support for relative dates on --date argument

.scripts/tests-e2e.sh

@@ -81,6 +81,10 @@ assertSuccess "kosmorro -h"
 assertSuccess "kosmorro -d 2020-01-27"
 assertFailure "kosmorro -d yolo-yo-lo"
 assertFailure "kosmorro -d 2020-13-32"
+assertSuccess "kosmorro --date='+3y 5m3d'"
+assertSuccess "kosmorro --date='-1y3d'"
+assertFailure "kosmorro --date='+3d4m"
+assertFailure "kosmorro -date='3y'"
 assertSuccess "kosmorro --latitude=50.5876 --longitude=3.0624"
 assertSuccess "kosmorro --latitude=50.5876 --longitude=3.0624 -d 2020-01-27"
 assertSuccess "kosmorro --latitude=50.5876 --longitude=3.0624 -d 2020-01-27 --timezone=1"

Pipfile

@@ -16,6 +16,7 @@ tabulate = "*"
 numpy = ">=1.17.0,<2.0.0"
 termcolor = "*"
 latex = "*"
+python-dateutil = "*"
 
 [requires]
 python_version = "3"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "67748949d467fbdca22ccc963430b21be215566f8a49b56ac734b44023ce5ff2"
+            "sha256": "4bcfaa3140b0b5c03886cf6877b37a1eb9df4e175f43d3ce0c1312496cde8515"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -82,6 +82,14 @@
             "index": "pypi",
             "version": "==1.18.2"
         },
+        "python-dateutil": {
+            "hashes": [
+                "sha256:73ebfe9dbf22e832286dafa60473e4cd239f8592f699aa5adaf10050e6e1823c",
+                "sha256:75bb3f31ea686f1197762692a9ee6a7550b59fc6ca3a1f4b5d7e32fb98e2da2a"
+            ],
+            "index": "pypi",
+            "version": "==2.8.1"
+        },
         "sgp4": {
             "hashes": [
                 "sha256:0e37751cf68d0b9d3417e4bcb1973e52f032b5dc29d57dd264f2e5c330ef9ce4",
@@ -177,10 +185,10 @@
         },
         "certifi": {
             "hashes": [
-                "sha256:017c25db2a153ce562900032d5bc68e9f191e44e9a0f762f373977de9df1fbb3",
-                "sha256:25b64c7da4cd7479594d035c08c2d809eb4aab3a26e5a990ea98cc450c320f1f"
+                "sha256:1d987a998c75633c40847cc966fcf5904906c920a7f17ef374f5aa4282abd304",
+                "sha256:51fcb31174be6e6664c5f69e3e1691a2d72a1a12e90f872cbdb1567eb47b6519"
             ],
-            "version": "==2019.11.28"
+            "version": "==2020.4.5.1"
         },
         "chardet": {
             "hashes": [
@@ -199,39 +207,39 @@
         },
         "coverage": {
             "hashes": [
-                "sha256:03f630aba2b9b0d69871c2e8d23a69b7fe94a1e2f5f10df5049c0df99db639a0",
-                "sha256:046a1a742e66d065d16fb564a26c2a15867f17695e7f3d358d7b1ad8a61bca30",
-                "sha256:0a907199566269e1cfa304325cc3b45c72ae341fbb3253ddde19fa820ded7a8b",
-                "sha256:165a48268bfb5a77e2d9dbb80de7ea917332a79c7adb747bd005b3a07ff8caf0",
-                "sha256:1b60a95fc995649464e0cd48cecc8288bac5f4198f21d04b8229dc4097d76823",
-                "sha256:1f66cf263ec77af5b8fe14ef14c5e46e2eb4a795ac495ad7c03adc72ae43fafe",
-                "sha256:2e08c32cbede4a29e2a701822291ae2bc9b5220a971bba9d1e7615312efd3037",
-                "sha256:3844c3dab800ca8536f75ae89f3cf566848a3eb2af4d9f7b1103b4f4f7a5dad6",
-                "sha256:408ce64078398b2ee2ec08199ea3fcf382828d2f8a19c5a5ba2946fe5ddc6c31",
-                "sha256:443be7602c790960b9514567917af538cac7807a7c0c0727c4d2bbd4014920fd",
-                "sha256:4482f69e0701139d0f2c44f3c395d1d1d37abd81bfafbf9b6efbe2542679d892",
-                "sha256:4a8a259bf990044351baf69d3b23e575699dd60b18460c71e81dc565f5819ac1",
-                "sha256:513e6526e0082c59a984448f4104c9bf346c2da9961779ede1fc458e8e8a1f78",
-                "sha256:5f587dfd83cb669933186661a351ad6fc7166273bc3e3a1531ec5c783d997aac",
-                "sha256:62061e87071497951155cbccee487980524d7abea647a1b2a6eb6b9647df9006",
-                "sha256:641e329e7f2c01531c45c687efcec8aeca2a78a4ff26d49184dce3d53fc35014",
-                "sha256:65a7e00c00472cd0f59ae09d2fb8a8aaae7f4a0cf54b2b74f3138d9f9ceb9cb2",
-                "sha256:6ad6ca45e9e92c05295f638e78cd42bfaaf8ee07878c9ed73e93190b26c125f7",
-                "sha256:73aa6e86034dad9f00f4bbf5a666a889d17d79db73bc5af04abd6c20a014d9c8",
-                "sha256:7c9762f80a25d8d0e4ab3cb1af5d9dffbddb3ee5d21c43e3474c84bf5ff941f7",
-                "sha256:85596aa5d9aac1bf39fe39d9fa1051b0f00823982a1de5766e35d495b4a36ca9",
-                "sha256:86a0ea78fd851b313b2e712266f663e13b6bc78c2fb260b079e8b67d970474b1",
-                "sha256:8a620767b8209f3446197c0e29ba895d75a1e272a36af0786ec70fe7834e4307",
-                "sha256:922fb9ef2c67c3ab20e22948dcfd783397e4c043a5c5fa5ff5e9df5529074b0a",
-                "sha256:9fad78c13e71546a76c2f8789623eec8e499f8d2d799f4b4547162ce0a4df435",
-                "sha256:a37c6233b28e5bc340054cf6170e7090a4e85069513320275a4dc929144dccf0",
-                "sha256:c3fc325ce4cbf902d05a80daa47b645d07e796a80682c1c5800d6ac5045193e5",
-                "sha256:cda33311cb9fb9323958a69499a667bd728a39a7aa4718d7622597a44c4f1441",
-                "sha256:db1d4e38c9b15be1521722e946ee24f6db95b189d1447fa9ff18dd16ba89f732",
-                "sha256:eda55e6e9ea258f5e4add23bcf33dc53b2c319e70806e180aecbff8d90ea24de",
-                "sha256:f372cdbb240e09ee855735b9d85e7f50730dcfb6296b74b95a3e5dea0615c4c1"
-            ],
-            "version": "==5.0.4"
+                "sha256:00f1d23f4336efc3b311ed0d807feb45098fc86dee1ca13b3d6768cdab187c8a",
+                "sha256:01333e1bd22c59713ba8a79f088b3955946e293114479bbfc2e37d522be03355",
+                "sha256:0cb4be7e784dcdc050fc58ef05b71aa8e89b7e6636b99967fadbdba694cf2b65",
+                "sha256:0e61d9803d5851849c24f78227939c701ced6704f337cad0a91e0972c51c1ee7",
+                "sha256:1601e480b9b99697a570cea7ef749e88123c04b92d84cedaa01e117436b4a0a9",
+                "sha256:2742c7515b9eb368718cd091bad1a1b44135cc72468c731302b3d641895b83d1",
+                "sha256:2d27a3f742c98e5c6b461ee6ef7287400a1956c11421eb574d843d9ec1f772f0",
+                "sha256:402e1744733df483b93abbf209283898e9f0d67470707e3c7516d84f48524f55",
+                "sha256:5c542d1e62eece33c306d66fe0a5c4f7f7b3c08fecc46ead86d7916684b36d6c",
+                "sha256:5f2294dbf7875b991c381e3d5af2bcc3494d836affa52b809c91697449d0eda6",
+                "sha256:6402bd2fdedabbdb63a316308142597534ea8e1895f4e7d8bf7476c5e8751fef",
+                "sha256:66460ab1599d3cf894bb6baee8c684788819b71a5dc1e8fa2ecc152e5d752019",
+                "sha256:782caea581a6e9ff75eccda79287daefd1d2631cc09d642b6ee2d6da21fc0a4e",
+                "sha256:79a3cfd6346ce6c13145731d39db47b7a7b859c0272f02cdb89a3bdcbae233a0",
+                "sha256:7a5bdad4edec57b5fb8dae7d3ee58622d626fd3a0be0dfceda162a7035885ecf",
+                "sha256:8fa0cbc7ecad630e5b0f4f35b0f6ad419246b02bc750de7ac66db92667996d24",
+                "sha256:a027ef0492ede1e03a8054e3c37b8def89a1e3c471482e9f046906ba4f2aafd2",
+                "sha256:a3f3654d5734a3ece152636aad89f58afc9213c6520062db3978239db122f03c",
+                "sha256:a82b92b04a23d3c8a581fc049228bafde988abacba397d57ce95fe95e0338ab4",
+                "sha256:acf3763ed01af8410fc36afea23707d4ea58ba7e86a8ee915dfb9ceff9ef69d0",
+                "sha256:adeb4c5b608574a3d647011af36f7586811a2c1197c861aedb548dd2453b41cd",
+                "sha256:b83835506dfc185a319031cf853fa4bb1b3974b1f913f5bb1a0f3d98bdcded04",
+                "sha256:bb28a7245de68bf29f6fb199545d072d1036a1917dca17a1e75bbb919e14ee8e",
+                "sha256:bf9cb9a9fd8891e7efd2d44deb24b86d647394b9705b744ff6f8261e6f29a730",
+                "sha256:c317eaf5ff46a34305b202e73404f55f7389ef834b8dbf4da09b9b9b37f76dd2",
+                "sha256:dbe8c6ae7534b5b024296464f387d57c13caa942f6d8e6e0346f27e509f0f768",
+                "sha256:de807ae933cfb7f0c7d9d981a053772452217df2bf38e7e6267c9cbf9545a796",
+                "sha256:dead2ddede4c7ba6cb3a721870f5141c97dc7d85a079edb4bd8d88c3ad5b20c7",
+                "sha256:dec5202bfe6f672d4511086e125db035a52b00f1648d6407cc8e526912c0353a",
+                "sha256:e1ea316102ea1e1770724db01998d1603ed921c54a86a2efcb03428d5417e489",
+                "sha256:f90bfc4ad18450c80b024036eaf91e4a246ae287701aaa88eaebebf150868052"
+            ],
+            "version": "==5.1"
         },
         "idna": {
             "hashes": [

kosmorrolib/core.py

@@ -21,10 +21,15 @@ import re
 from shutil import rmtree
 from pathlib import Path
 
+from datetime import date
+from dateutil.relativedelta import relativedelta
+
 from skyfield.api import Loader
 from skyfield.timelib import Time
 from skyfield.nutationlib import iau2000b
 
+from kosmorrolib.i18n import _
+
 CACHE_FOLDER = str(Path.home()) + '/.kosmorro-cache'
 
 class Environment:
@@ -86,3 +91,29 @@ def flatten_list(the_list: list):
         new_list.append(item)
 
     return new_list
+
+
+def get_date(date_arg: str) -> date:
+    if re.match(r'^\d{4}-\d{2}-\d{2}$', date_arg):
+        try:
+            return date.fromisoformat(date_arg)
+        except ValueError as error:
+            raise ValueError(_('The date {date} is not valid: {error}').format(date=date_arg, error=error.args[0]))
+    elif re.match(r'^([+-])(([0-9]+)y)?[ ]?(([0-9]+)m)?[ ]?(([0-9]+)d)?$', date_arg):
+        def get_offset(date_arg: str, signifier: str):
+            if re.search(r'([0-9]+)' + signifier, date_arg):
+                return abs(int(re.search(r'[+-]?([0-9]+)' + signifier, date_arg).group(0)[:-1]))
+            return 0
+
+        days = get_offset(date_arg, 'd')
+        months = get_offset(date_arg, 'm')
+        years = get_offset(date_arg, 'y')
+
+
+        if date_arg[0] == '+':
+            return date.today() + relativedelta(days=days, months=months, years=years)
+        return date.today() - relativedelta(days=days, months=months, years=years)
+
+    else:
+        error_msg = _('The date {date} does not match the required YYYY-MM-DD format or the offset format.')
+        raise ValueError(error_msg.format(date=date_arg))

kosmorrolib/locales/messages.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: kosmorro 0.7.0\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2020-04-05 10:47+0200\n"
+"POT-Creation-Date: 2020-04-16 17:57+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -17,6 +17,16 @@ msgstr ""
 "Content-Transfer-Encoding: 8bit\n"
 "Generated-By: Babel 2.8.0\n"
 
+#: kosmorrolib/core.py:101
+msgid "The date {date} is not valid: {error}"
+msgstr ""
+
+#: kosmorrolib/core.py:118
+msgid ""
+"The date {date} does not match the required YYYY-MM-DD format or the "
+"offset format."
+msgstr ""
+
 #: kosmorrolib/data.py:32
 msgid "New Moon"
 msgstr ""
@@ -211,80 +221,72 @@ msgstr ""
 msgid "Selected output format needs an output file (--output)."
 msgstr ""
 
-#: kosmorrolib/main.py:104
-msgid "The date {date} does not match the required YYYY-MM-DD format."
-msgstr ""
-
-#: kosmorrolib/main.py:109
-msgid "The date {date} is not valid: {error}"
-msgstr ""
-
-#: kosmorrolib/main.py:123
+#: kosmorrolib/main.py:115
 msgid "Running on Python {python_version}"
 msgstr ""
 
-#: kosmorrolib/main.py:129
+#: kosmorrolib/main.py:121
 msgid "Do you really want to clear Kosmorro's cache? [yN] "
 msgstr ""
 
-#: kosmorrolib/main.py:136
+#: kosmorrolib/main.py:128
 msgid "Answer did not match expected options, cache not cleared."
 msgstr ""
 
-#: kosmorrolib/main.py:145
+#: kosmorrolib/main.py:137
 msgid ""
 "Compute the ephemerides and the events for a given date, at a given "
 "position on Earth."
 msgstr ""
 
-#: kosmorrolib/main.py:147
+#: kosmorrolib/main.py:139
 msgid ""
 "By default, only the events will be computed for today ({date}).\n"
 "To compute also the ephemerides, latitude and longitude arguments are "
 "needed."
 msgstr ""
 
-#: kosmorrolib/main.py:152
+#: kosmorrolib/main.py:144
 msgid "Show the program version"
 msgstr ""
 
-#: kosmorrolib/main.py:154
+#: kosmorrolib/main.py:146
 msgid "Delete all the files Kosmorro stored in the cache."
 msgstr ""
 
-#: kosmorrolib/main.py:156
+#: kosmorrolib/main.py:148
 msgid "The format under which the information have to be output"
 msgstr ""
 
-#: kosmorrolib/main.py:158
+#: kosmorrolib/main.py:150
 msgid ""
 "The observer's latitude on Earth. Can also be set in the "
 "KOSMORRO_LATITUDE environment variable."
 msgstr ""
 
-#: kosmorrolib/main.py:161
+#: kosmorrolib/main.py:153
 msgid ""
 "The observer's longitude on Earth. Can also be set in the "
 "KOSMORRO_LONGITUDE environment variable."
 msgstr ""
 
-#: kosmorrolib/main.py:164
+#: kosmorrolib/main.py:156
 msgid ""
 "The date for which the ephemerides must be computed (in the YYYY-MM-DD "
 "format). Defaults to the current date ({default_date})"
 msgstr ""
 
-#: kosmorrolib/main.py:168
+#: kosmorrolib/main.py:160
 msgid ""
 "The timezone to display the hours in (e.g. 2 for UTC+2 or -3 for UTC-3). "
 "Can also be set in the KOSMORRO_TIMEZONE environment variable."
 msgstr ""
 
-#: kosmorrolib/main.py:171
+#: kosmorrolib/main.py:163
 msgid "Disable the colors in the console."
 msgstr ""
 
-#: kosmorrolib/main.py:173
+#: kosmorrolib/main.py:165
 msgid ""
 "A file to export the output to. If not given, the standard output is "
 "used. This argument is needed for PDF format."

kosmorrolib/main.py

@@ -42,7 +42,7 @@ def main():
         return 0 if args.special_action() else 1
 
     try:
-        compute_date = get_date(args.date)
+        compute_date = core.get_date(args.date)
     except ValueError as error:
         print(colored(error.args[0], color='red', attrs=['bold']))
         return -1
@@ -99,14 +99,6 @@ def main():
     return 0
 
 
-def get_date(yyyymmdd: str) -> date:
-    if not re.match(r'^\d{4}-\d{2}-\d{2}$', yyyymmdd):
-        raise ValueError(_('The date {date} does not match the required YYYY-MM-DD format.').format(date=yyyymmdd))
-
-    try:
-        return date.fromisoformat(yyyymmdd)
-    except ValueError as error:
-        raise ValueError(_('The date {date} is not valid: {error}').format(date=yyyymmdd, error=error.args[0]))
 
 
 def get_dumpers() -> {str: dumper.Dumper}:

manpage/kosmorro.1.md

@@ -23,7 +23,7 @@
     the observer's longitude on Earth
 
 `--date=`_DATE_, `-d` _DATE_  
-    The date for which the ephemerides must be computed (in the YYYY-MM-DD format); defaults to the current date
+    The date for which the ephemerides must be computed, either in the YYYY-MM-DD format or as an interval in the "[+-]YyMmDd" format (with Y, M, and D numbers); defaults to the current date
 
 `--timezone=`_TIMEZONE_, `-t` _TIMEZONE_  
     the timezone to display the hours in; e.g. 2 for UTC+2 or -3 for UTC-3

setup.py

@@ -41,7 +41,7 @@ setup(
     data_files=[
         ('man/man1', ['manpage/kosmorro.1'])
     ],
-    install_requires=['skyfield>=1.17.0,<2.0.0', 'tabulate', 'numpy>=1.17.0,<2.0.0', 'termcolor'],
+    install_requires=['skyfield>=1.17.0,<2.0.0', 'tabulate', 'numpy>=1.17.0,<2.0.0', 'termcolor', 'python-dateutil'],
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Operating System :: POSIX :: Linux',

test/core.py

@@ -3,6 +3,9 @@ import unittest
 import os
 import kosmorrolib.core as core
 
+from datetime import date
+from dateutil.relativedelta import relativedelta
+
 
 class CoreTestCase(unittest.TestCase):
     def test_flatten_list(self):
@@ -27,6 +30,10 @@ class CoreTestCase(unittest.TestCase):
 
         self.assertEqual("{'great_variable': 'value', 'another_variable': 'another value'}", str(env))
 
+    def test_date_arg_parsing(self):
+        self.assertEqual(core.get_date("+1y 2m3d"), date.today() + relativedelta(years=1, months=2, days=3))
+        self.assertEqual(core.get_date("-1y2d"), date.today() - relativedelta(years=1, days=2))
+        self.assertEqual(core.get_date("1111-11-13"), date(1111, 11, 13))
 
 if __name__ == '__main__':
     unittest.main()