This code from the Polling case study polls.select_dtypes('object').head() date_cols = ['startdate','enddate'] polls[date_cols] = polls[date_cols].apply(pd.to_datetime) a. selects the columns with the object data type and converts two of them to the datetime data type b. selects the columns with the object data type and converts one of them to the datetime data type c. displays the columns with the object data type and converts two of them to the datetime data type d. displays the columns with the object data type and converts one of them to the datetime data type
Answer (2)
The question pertains to a piece of code using the pandas library, which is a powerful tool for data manipulation and analysis in Python. Let's break down what this code does step by step:
polls.select_dtypes('object').head()
This line selects columns from the DataFrame named polls that have the data type 'object'. In pandas, a column with the data type 'object' typically contains strings or mixed data. The .head() function is used to display the first few rows of these selected columns.
date_cols = ['startdate','enddate']
This line creates a list called date_cols that contains the names of the columns 'startdate' and 'enddate'. These are the columns that you want to convert from 'object' type to the 'datetime' type.
polls[date_cols] = polls[date_cols].apply(pd.to_datetime)
This line converts the data type of the columns specified in date_cols from strings (or 'object' type) into datetime objects. This is done using the apply() function along with pd.to_datetime, which is a pandas function that parses an argument into a datetime object.
By carefully analyzing these steps, we can see that the code does two main tasks:
It displays the columns of type 'object'.
It converts two of the specified object-type columns ('startdate' and 'enddate') into datetime objects.
Combining these insights, the correct multiple-choice option that matches this explanation is:
c. displays the columns with the object data type and converts two of them to the datetime data type.
This confirms that the code snippet is correctly transforming the specified string-based date columns to a more usable datetime format for further analysis.
The code snippet selects and displays columns with the object data type and converts two specific columns, 'startdate' and 'enddate', to the datetime data type. The correct answer choice is c. This transformation is essential for proper date analysis within the DataFrame.
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