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

Pandas Datetime: Exercise-22 with Solution

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.

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
hour_v_year = df.pivot_table(columns=df['Date_time'].dt.hour,index=df['Date_time'].dt.year.apply(is_top_years),aggfunc='count',values='city')
hour_v_year.columns = hour_v_year.columns.astype(int)
hour_v_year.columns = hour_v_year.columns.astype(str) + ":00"
hour_v_year.index = hour_v_year.index.astype(int)
print("\nComparison of the top 10 years in which the UFO was sighted vs the hours of the day:")
print(hour_v_year.head(10))

Sample Output:

Comparison of the top 10 years in which the UFO was sighted vs the hours of the day:
           0:00  1:00  2:00  4:00  ...    20:00  21:00  22:00  23:00
Date_time                          ...                              
1993        1.0   1.0   1.0   NaN  ...      2.0    NaN    NaN    4.0
1994        NaN   NaN   NaN   NaN  ...      NaN    4.0    2.0    1.0
1995        NaN   NaN   1.0   1.0  ...      2.0    1.0    1.0    3.0
1996        NaN   1.0   NaN   NaN  ...      1.0    NaN    2.0    1.0
1997        NaN   1.0   NaN   1.0  ...      NaN    4.0    1.0    2.0
1998        2.0   1.0   NaN   NaN  ...      2.0    2.0    2.0    NaN
1999        2.0   NaN   1.0   NaN  ...      NaN    2.0    1.0    2.0
2000        NaN   NaN   1.0   NaN  ...      4.0    2.0    2.0    1.0
2001        3.0   1.0   NaN   1.0  ...      1.0    5.0    NaN    NaN
2002        NaN   1.0   NaN   NaN  ...      2.0    NaN    NaN    3.0

[10 rows x 20 columns]

Python Code Editor:


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

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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