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Getting today's date in YYYY-MM-DD in Python?

python
date-formatting
datetime
pythonic-way
Nikita BarsukovbyNikita Barsukov·Sep 17, 2024
TLDR

Get today's date in YYYY-MM-DD format utilizing Python's datetime module. The key functions are today() and strftime('%Y-%m-%d'). Check out this optimised code snippet:

from datetime import date print(date.today().strftime('%Y-%m-%d')) # Warning: Consuming this date does not impact your calendar knowledge!

With this line, you'll instantly print out today's date in YYYY-MM-DD format.

The flow of time: Essentials of Python date formatting

Diving deeper into Python's date formatting, one needs a clear understanding of certain core elements. Here’s a look into the fine details.

Time zones: Does anyone really know what time it is?

  • datetime.today() fetches the current local date, while datetime.utcnow() provides the current date in UTC. Remember this when you're coding for servers that have clients spread across different time zones.
  • Consider Daylight Saving Time (DST) in applications requiring time display. Lack of proper handling could lead to hour-long discrepancies in time!

Readability vs. Efficiency: The Pythonic way

  • Obtain dates in ISO 8601 format (which is just YYYY-MM-DD) using the isoformat() function. It's not only a shortcut, it's handy and it avoids potential confusion faced across region-specific date formats.
  • You could fetch dates using str(datetime.datetime.today()).split()[0] but it's less tidy and invites more errors than other methods.

Third-party libraries: When built-ins aren't enough

  • For more complex operations with dates and time, arrow, a third-party library, could be your tool. It handles time zones, formatting, and parsing dates like a seasoned chronomancer.

Spilling the beans: Additional pointers and common faux pas

The trick with strftime

  • Use %m and %d to maintain the YYYY-MM-DD format, especially with single-digit days and months. After all, nobody likes a lopsided date.
  • The strftime function holds the power of time in its hand. Make sure you channel it using the right format specifiers.

Time zones: It's relative!

  • Be wary of today() and utcnow(). They bats for the home team! By that I mean, they are completely ignorant of time zones.

A word of caution

  • Slicing through or splitting string representations of datetime objects might seem like a tempting magic trick, but it only leads to error-prone, non-idiomatic code.

Performance vs. Quantity: Less is more!

  • When efficiency is crucial, nothing beats built-in datetime functionality. After all, brevity is the soul of wit, they say... and code!

Real-world scenarios

Handling user inputs

  • User input for dates can be a chaotic experience. Make sure you gracefully handle various date formats and consistently convert them into YYYY-MM-DD for downstream processing or storage.

Managing databases

  • Different databases have distinct date formats. You might need to convert to and from the YYYY-MM-DD format—based on the database and your chosen ORM.

Logging and reporting

  • Logging and reporting often favor YYYY-MM-DD format, as it is easy on the eyes and automatically sorts chronologically. Plus, machines like it!