PANDAS DATAFRAMES AND CSV FILES

The code samples in several earlier sections contain hard-coded data inside the Python scripts. However, it’s also very common to read data from a CSV file. You can use the Python csv.reader() function, the NumPy loadtxt() function, or the Pandas function read_csv() function (shown in this section) to read the contents of CSV files.

Listing 3.17 displays the contents of the CSV file weather_data.csv and Listing 3.18 displays the contents of weather_data.py that illustrates how to read the CSV weather_data.csv.

LISTING 3.17: weather_data.csv

day,temperature,windspeed,event
7/1/2018,42,16,Rain
7/2/2018,45,3,Sunny
7/3/2018,78,12,Snow
7/4/2018,74,9,Snow
7/5/2018,42,24,Rain
7/6/2018,51,32,Sunny

LISTING 3.18: weather_data.py

import pandas as pd

df = pd.read_csv("weather_data.csv")

print(df)
print(df.shape)  # rows, columns
print(df.head()) # df.head(3)
print(df.tail())
print(df[1:3])
print(df.columns)
print(type(df['day']))
print...