Pandas Datetime: Create a comparison of the top 10 years in which the UFO was sighted vs each Month

Last update on May 28 2022 13:40:42 (UTC/GMT +8 hours)

Pandas Datetime: Exercise-23 with Solution

Write a Pandas program to create a comparison of the top 10 years in which the UFO was sighted vs each Month.

Sample Solution:

Python Code:

import pandas as pd
#Source: https://bit.ly/1l9yjm9
df = pd.read_csv(r'ufo.csv')
df['Date_time'] = df['Date_time'].astype('datetime64[ns]')
most_sightings_years = df['Date_time'].dt.year.value_counts().head(10)
def is_top_years(year):
   if year in most_sightings_years.index:
       return year
month_vs_year = df.pivot_table(columns=df['Date_time'].dt.month,index=df['Date_time'].dt.year.apply(is_top_years),aggfunc='count',values='city')
month_vs_year.index = month_vs_year.index.astype(int)
month_vs_year.columns = month_vs_year.columns.astype(int)
print("\nComparison of the top 10 years in which the UFO was sighted vs each month:")
print(month_vs_year.head(10))

Sample Output:

Comparison of the top 10 years in which the UFO was sighted vs each month:
Date_time   1    2    3    4    5    6    7    8    9    10   11   12
Date_time                                                            
1993       NaN  NaN  1.0  1.0  NaN  1.0  3.0  2.0  3.0  NaN  1.0  NaN
1994       2.0  NaN  3.0  2.0  2.0  NaN  NaN  1.0  NaN  NaN  NaN  1.0
1995       2.0  1.0  NaN  1.0  1.0  1.0  3.0  NaN  1.0  NaN  2.0  NaN
1996       NaN  1.0  NaN  1.0  1.0  1.0  3.0  3.0  1.0  NaN  1.0  NaN
1997       NaN  2.0  1.0  NaN  2.0  1.0  3.0  1.0  1.0  1.0  1.0  1.0
1998       1.0  2.0  1.0  3.0  NaN  2.0  1.0  NaN  NaN  1.0  NaN  2.0
1999       NaN  NaN  2.0  NaN  1.0  2.0  4.0  NaN  NaN  1.0  NaN  1.0
2000       NaN  3.0  2.0  NaN  2.0  1.0  1.0  NaN  NaN  NaN  1.0  2.0
2001       2.0  1.0  2.0  2.0  1.0  2.0  NaN  1.0  2.0  NaN  1.0  1.0
2002       3.0  1.0  1.0  NaN  3.0  NaN  2.0  1.0  2.0  1.0  NaN  NaN

Python Code Editor:

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Previous: Write a Pandas program to create a comparison of the top 10 years in which the UFO was sighted vs the hours of the day.
Next: Write a Pandas program to create a heatmap (rectangular data as a color-encoded matrix) for comparison of the top 10 years in which the UFO was sighted vs each Month.

Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

The os and os.path modules.

The __file__ constant

os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")

os.path.dirname(path) (returns "the directory name of pathname path")

os.getcwd() (returns "a string representing the current working directory")

os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m