Date and Time Parsing

def parse(timestr, parserinfo=None, **kwargs):
    """
    Parse a date/time string into a datetime object.
    
    Parameters:
    - timestr (str): String containing date and/or time
    - parserinfo (parserinfo, optional): Parser configuration object
    - default (datetime, optional): Default datetime for missing components
    - ignoretz (bool): If True, ignore timezone info and return naive datetime
    - tzinfos (dict/callable, optional): Additional timezone name mappings
    - dayfirst (bool): Interpret ambiguous dates as day-first (DD/MM/YYYY)
    - yearfirst (bool): Interpret ambiguous dates as year-first (YYYY/MM/DD)  
    - fuzzy (bool): Ignore unknown tokens in the string
    - fuzzy_with_tokens (bool): Return (datetime, tokens) tuple with unknown tokens
    
    Returns:
    datetime: Parsed datetime object
    
    Raises:
    ParserError: When string cannot be parsed
    """

class ParserError(ValueError):
    """Raised when a date/time string cannot be parsed."""

from dateutil.parser import parse
from datetime import datetime

# Basic parsing - various formats
dt1 = parse("2023-12-25")                    # ISO format
dt2 = parse("Dec 25, 2023")                  # Named month
dt3 = parse("25/12/2023")                    # Ambiguous format
dt4 = parse("2023-12-25T14:30:00Z")          # ISO with timezone

# Ambiguous date resolution
parse("12/25/2023")                          # Assumes MM/DD/YYYY (US)
parse("12/25/2023", dayfirst=True)           # Forces DD/MM/YYYY (EU)
parse("2023/12/25", yearfirst=True)          # YYYY/MM/DD format

# Default values for missing components
default = datetime(2023, 1, 1, 9, 0, 0)
parse("Dec 25", default=default)             # Uses year/time from default

# Timezone handling
parse("2023-12-25 14:30 EST")                # With timezone name
parse("2023-12-25 14:30 +0500")             # With offset
parse("2023-12-25 14:30 EST", ignoretz=True) # Ignore timezone

# Fuzzy parsing
parse("Today is Dec 25, 2023", fuzzy=True)   # Extracts date from text
dt, tokens = parse("Event on Dec 25, 2023 at venue", fuzzy_with_tokens=True)

def isoparse(dt_str):
    """
    Parse ISO-8601 formatted date/time strings.
    
    Parameters:
    - dt_str (str): ISO-8601 formatted string
    
    Returns:
    datetime: Parsed datetime object
    
    Raises:
    ValueError: When string is not valid ISO-8601 format
    """

class isoparser:
    def __init__(self, sep=None):
        """
        ISO-8601 parser with configurable date/time separator.
        
        Parameters:
        - sep (str, optional): Custom separator between date and time parts
        """
        
    def isoparse(self, dt_str):
        """Parse ISO-8601 string using this parser instance."""

from dateutil.parser import isoparse, isoparser

# Standard ISO-8601 formats
dt1 = isoparse("2023-12-25")                 # Date only
dt2 = isoparse("2023-12-25T14:30:00")        # Date and time
dt3 = isoparse("2023-12-25T14:30:00Z")       # With UTC timezone
dt4 = isoparse("2023-12-25T14:30:00+05:00")  # With offset timezone
dt5 = isoparse("2023-12-25 14:30:00")        # Space separator

# Custom parser with different separator
parser = isoparser(sep='_')
dt = parser.isoparse("2023-12-25_14:30:00")

DEFAULTPARSER: parser
    """Default parser instance used by module-level parse() function."""

DEFAULTTZPARSER: parser  
    """Default timezone-aware parser instance for internal use."""

class parser:
    def __init__(self, parserinfo=None):
        """
        Create a parser with custom configuration.
        
        Parameters:
        - parserinfo (parserinfo, optional): Parser configuration object
        """
        
    def parse(self, timestr, default=None, ignoretz=False, tzinfos=None, **kwargs):
        """
        Parse date/time string using this parser's configuration.
        
        Parameters: Same as module-level parse() function
        Returns: datetime object
        """

class parserinfo:
    def __init__(self, dayfirst=False, yearfirst=False):
        """
        Parser configuration for locale-specific parsing.
        
        Parameters:
        - dayfirst (bool): Default day-first interpretation
        - yearfirst (bool): Default year-first interpretation
        """
        
    # Configuration attributes
    JUMP: list[str]        # Words to ignore ("at", "on", "the")
    WEEKDAYS: list[list[str]]  # Weekday names by language
    MONTHS: list[list[str]]    # Month names by language  
    HMS: list[list[str]]       # Hour/minute/second indicators
    AMPM: list[str]           # AM/PM indicators
    UTCZONE: list[str]        # UTC timezone names
    PERTAIN: list[str]        # Pertaining words ("of", "in")

from dateutil.parser import parser, parserinfo

# Custom parser info for different locale
class CustomParserInfo(parserinfo):
    MONTHS = [
        ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
        ["Januar", "Februar", "März", "April", "Mai", "Juni",
         "Juli", "August", "September", "Oktober", "November", "Dezember"]
    ]

custom_parser = parser(CustomParserInfo())
dt = custom_parser.parse("25 März 2023")  # German month name

# Parser with default settings
eu_parser = parser(parserinfo(dayfirst=True))
us_parser = parser(parserinfo(dayfirst=False))

dt_eu = eu_parser.parse("12/03/2023")  # March 12, 2023
dt_us = us_parser.parse("12/03/2023")  # December 3, 2023

class UnknownTimezoneWarning(RuntimeWarning):
    """Warning issued when encountering unknown timezone names."""

# Timezone resolution in parse() function
def parse(timestr, tzinfos=None, **kwargs):
    """
    tzinfos parameter options:
    - dict: Mapping of timezone names to tzinfo objects
    - callable: Function that takes timezone name and returns tzinfo object
    """

from dateutil.parser import parse
from dateutil.tz import gettz

# Custom timezone mappings
custom_timezones = {
    'EST': gettz('America/New_York'),
    'PST': gettz('America/Los_Angeles'),
    'JST': gettz('Asia/Tokyo')
}

dt = parse("2023-12-25 14:30 JST", tzinfos=custom_timezones)

# Dynamic timezone resolution
def resolve_timezone(tzname):
    """Custom timezone resolver function."""
    timezone_map = {
        'ET': 'America/New_York',
        'PT': 'America/Los_Angeles',
        'MT': 'America/Denver'
    }
    if tzname in timezone_map:
        return gettz(timezone_map[tzname])
    return None

dt = parse("2023-12-25 14:30 ET", tzinfos=resolve_timezone)

from dateutil.parser import parse

text = "Meeting scheduled for December 25th, 2023 at the main office"
dt, tokens = parse(text, fuzzy_with_tokens=True)
print(f"Date: {dt}")
print(f"Ignored tokens: {tokens}")  # ['Meeting', 'scheduled', 'for', 'at', 'the', 'main', 'office']

from dateutil.parser import parse, ParserError

date_strings = [
    "2023-12-25",
    "Dec 25, 2023", 
    "25/12/2023",
    "invalid date"
]

parsed_dates = []
for date_str in date_strings:
    try:
        dt = parse(date_str, dayfirst=True)
        parsed_dates.append(dt)
    except ParserError:
        print(f"Could not parse: {date_str}")

from dateutil.parser import parse, isoparse

# For ISO-8601 strings, isoparse is much faster
iso_string = "2023-12-25T14:30:00Z"
dt_fast = isoparse(iso_string)      # Faster
dt_slow = parse(iso_string)         # Slower but more flexible

# For non-ISO strings, use parse
natural_string = "Dec 25, 2023 2:30 PM"
dt = parse(natural_string)  # Only option

# Standard datetime types (from datetime module)
from datetime import datetime, tzinfo

# Parser-specific exceptions
class ParserError(ValueError):
    """Exception raised when parsing fails."""

class UnknownTimezoneWarning(RuntimeWarning):
    """Warning for unknown timezone names."""

# Parser configuration types
class parserinfo:
    JUMP: list[str]
    WEEKDAYS: list[list[str]]
    MONTHS: list[list[str]]
    HMS: list[list[str]]
    AMPM: list[str] 
    UTCZONE: list[str]
    PERTAIN: list[str]

# Timezone info parameter types
TzInfos = dict[str, tzinfo] | callable[[str], tzinfo | None] | None