130 lines
3 KiB
Markdown
130 lines
3 KiB
Markdown
---
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tags:
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- python
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- time
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---
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# Dates in Python
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Python's built-in `datetime` module provides various classes for manipulating
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dates and times.
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### Importing `datetime`
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```python
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import datetime
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```
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### Getting Current Date and Time
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Get the current date and time using `datetime.datetime.now()`.
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```python
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current_datetime = datetime.datetime.now()
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print("Current datetime:", current_datetime)
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```
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### Creating Date Objects
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To create a date object, use `datetime.date`, specifying the year, month, and
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day.
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```python
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some_date = datetime.date(2021, 9, 30)
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print("Some date:", some_date)
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```
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### Creating Time Objects
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To create a time object, use `datetime.time`, specifying the hour, minute,
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second, and optionally microsecond.
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```python
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some_time = datetime.time(13, 24, 56)
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print("Some time:", some_time)
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```
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### Creating Datetime Objects
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To create a datetime object, use `datetime.datetime`.
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```python
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some_datetime = datetime.datetime(2021, 9, 30, 13, 24, 56)
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print("Some datetime:", some_datetime)
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```
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### Extracting components
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Extract components from a datetime object:
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```python
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print("Year:", some_datetime.year)
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print("Month:", some_datetime.month)
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print("Day:", some_datetime.day)
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print("Hour:", some_datetime.hour)
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print("Minute:", some_datetime.minute)
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print("Second:", some_datetime.second)
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```
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### Formatting `datetime` objects: `strftime`
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The `strftime` method (_string format time_) converts a datetime object to a
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string according to the specified format.
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This would typically be used when we have been working with a computer-friendly
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format of a date such as unix seconds which we then want to output in a more
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readable format.
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Use `strftime` to express the current date as YYYY-MM:
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```python
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now = datetime.now()
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formatted = now.strftime('%Y-%m')
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print(formatted)
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# 2024-06
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```
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Express the current date as YYYY-MM-DD H:M:S:
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```python
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formatted_datetime = some_datetime.strftime('%Y-%m-%d %H:%M:%S')
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print("Formatted datetime:", formatted_datetime)
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```
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Express a [unix timestamp](./Time_and_computers.md) as DD-MM-YYYY:
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```py
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def convert_timestamp(timestamp):
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date_object = datetime.datetime.fromtimestamp(timestamp)
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formatted_date = date_object.strftime("%d-%m-%Y")
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return formatted_date
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converted = convert_timestamp(1689023491)
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print(converted)
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# 10-07-2023
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```
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### Parsing `datetime` strings: `strptime`.
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The `strptime` (_string_parse_time) method_ parses a string representing a date
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and/or a time according to a specified format and returns a `datetime` object.
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Typically be used when want to carry out some sort of transformation on time
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data that we are sourcing in a particular format.
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Receive a date in the format DD-MM-YYYY and convert to datetime object:
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```python
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date_string = "18-06-2024"
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datetime_object = datetime.strptime(date_string, '%d-%m-%Y')
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print(date_object) # 2024-06-18 00:00:00
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```
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Extract the year from a UTC date format:
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```python
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datetime_obj = datetime.strptime("2024-03-27T10:44:28Z", "%Y%m%dT%H%M%SZ")
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print(datetime_obj.strftime('%Y'))
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# 2024
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```
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