Extracting Minute of the Hour from Timestamps with Python Pandas

πŸ’‘ Problem Formulation: When working with time series data in Python using Pandas, you might often need to extract specific elements from timestamps, such as the minute of the hour. For instance, given a Pandas Period or Timestamp, say ‘2023-03-20 14:45′, the task is to retrieve the minute component ’45’.

Method 1: Using Period.minute Attribute

The Period.minute attribute in Pandas is a straightforward way to access the minute element of a time period. When you have a Period object, this attribute returns the minute part as an integer.

Here’s an example:

import pandas as pd

# Creating a Period object
period = pd.Period('2023-03-20 14:45', freq='T')

# Accessing the minute component
minute = period.minute
print(minute)

Output:

45

The code snippet creates a Pandas Period object at a minute frequency and uses the .minute attribute to access the minute component of the period, which in this case is 45.

Method 2: Using Timestamp.minute Attribute

Similar to Period objects, Pandas provides a .minute attribute for Timestamp objects, which returns the minutes of the timestamp, making it useful for extracting the desired time component directly.

Here’s an example:

import pandas as pd

# Creating a Timestamp object
timestamp = pd.Timestamp('2023-03-20 14:45')

# Getting the minute of the hour
minute = timestamp.minute
print(minute)

Output:

45

The code demonstrates the creation of a Pandas Timestamp object and retrieves the minute component by using the .minute attribute, yielding the expected result of 45.

Method 3: Using dt Accessor with DataFrame or Series

You can use the dt accessor to extract the minute component from Series objects containing datetime information. This is particularly useful when working with columns of timestamps in a DataFrame.

Here’s an example:

import pandas as pd

# Creating a Series of Timestamps
timestamps = pd.Series(pd.date_range(start='2023-03-20 14:45', periods=3, freq='30T'))

# Extracting minutes of the hour
minutes = timestamps.dt.minute
print(minutes)

Output:

0    45
1    15
2    45
dtype: int64

The example introduces a Series object with a range of Timestamps and utilizes the dt.minute accessor to obtain a Series of minutes corresponding to each timestamp.

Method 4: Using to_datetime and Formatting Strings

If you’re dealing with string representations of dates and times, you can convert them into Timestamp objects using pd.to_datetime method. Afterwards, you can format the datetime to extract just the minute part.

Here’s an example:

import pandas as pd

# Converting a string to Timestamp
timestamp = pd.to_datetime('2023-03-20 14:45')

# Formatting to extract the minute
minute = timestamp.strftime('%M')
print(minute)

Output:

'45'

This snippet demonstrates converting a date string to a Timestamp object and then formatting it to a string representing only the minute portion, which gives us the string ’45’.

Bonus One-Liner Method 5: Using List Comprehension with Timestamp.minute

For situations where you have a list of string timestamps, a concise one-liner using a list comprehension along with the Timestamp.minute attribute can quickly extract the minutes component for each timestamp.

Here’s an example:

import pandas as pd

# List of timestamp strings
timestamps = ['2023-03-20 14:45', '2023-03-20 14:46', '2023-03-20 14:47']

# Extracting minutes using list comprehension
minutes = [pd.Timestamp(t).minute for t in timestamps]
print(minutes)

Output:

[45, 46, 47]

The example uses list comprehension to create Timestamp objects from a list of strings and subsequently accesses their minute component, resulting in a list of minutes: [45, 46, 47].

Summary/Discussion

Method 1: Period.minute Attribute. Direct and simple for handling period objects. Might not be suitable for other formats.Method 2: Timestamp.minute Attribute. Works great with single Timestamp objects but requires additional steps for string inputs.Method 3: dt Accessor with DataFrames or Series. Ideal for dataframe columns or series. Not applicable to individual Timestamp or Period objects.Method 4: Using to_datetime and Format Strings. Offers flexibility to handle strings but adds overhead due to conversion and formatting steps.Bonus Method 5: List Comprehension with Timestamp.minute. Quick and elegant for lists of timestamp strings but less readable for beginners.