﻿ Pandas Datetime: Get all the sighting days of the unidentified flying object (ufo) which are less than or equal to 40 years - w3resource

# Pandas Datetime: Get all the sighting days of the unidentified flying object (ufo) which are less than or equal to 40 years

## Pandas Datetime: Exercise-4 with Solution

Write a Pandas program to get all the sighting days of the unidentified flying object (ufo) which are less than or equal to 40 years (365*40 days).

Sample Solution :

Python Code :

``````import pandas as pd
import datetime
df['Date_time'] = df['Date_time'].astype('datetime64[ns]')
now = pd.to_datetime('today')
duration = datetime.timedelta(days=365*40)
print("Original Dataframe:")
print("\nCurrent date:")
print(now)
print("\nSighting days of the unidentified flying object (ufo) which are less than or equal to 40 years (365*40 days):")
df =  df[now - df['Date_time'] <= duration]
``````

Sample Output:

```Original Dataframe:
Date_time                  city     ...       latitude   longitude
0 1910-06-01 15:00:00           wills point     ...      32.709167  -96.008056
1 1920-06-11 21:00:00                cicero     ...      40.123889  -86.013333
2 1929-07-05 14:00:00  buchanan  (or burns)     ...      43.642500 -118.627500
3 1931-06-01 13:00:00               abilene     ...      38.917222  -97.213611
4 1939-06-01 20:00:00              waterloo     ...      34.918056  -88.064167

[5 rows x 11 columns]

Current date:
2019-07-11 11:55:03.162800

Sighting days of the unidentified flying object (ufo) which are less than or equal to 40 years (365*40 days):
Date_time          city     ...       latitude   longitude
149 1980-01-01 01:00:00  indianapolis     ...      39.768333  -86.158056
150 1980-01-01 23:30:00      chicopee     ...      42.148611  -72.608333
151 1980-03-01 00:30:00        oxford     ...      41.433889  -73.117222
152 1980-03-01 18:00:00        bisbee     ...      31.448056 -109.927778
153 1981-01-01 00:01:00      el cajon     ...      32.794722 -116.961667

[5 rows x 11 columns]
```

Python Code Editor:

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## Python: Tips of the Day

F strings:

It is a common practice to add variables inside strings. F strings are by far the coolest way of doing it. To appreciate the f strings more, let's first perform the operation with the format function.

```name = 'Owen'
age = 25
print("{} is {} years old".format(name, age))
```

Output:

```Owen is 25 years old
```

We specify the variables that go inside the curly braces by using the format function at the end. F strings allow for specifying the variables inside the string.

```name = 'Owen'
age = 25
print(f"{name} is {age} years old")
```

Output:

```Owen is 25 years old
```

F strings are easier to follow and type. Moreover, they make the code more readable.

```A, B, C = {2, 4, 6}
print(A, B, C)
A, B, C = ['p', 'q', 'r']
print(A, B, C)
```

Output:

```2 4 6
p q r
```