Course Content

Advanced Techniques in pandas

1. Getting Familiar With Indexing and Selecting Data

Outputting Columns by Title Outputting Rows by Index Selecting Specific Rows and Columns Learning More About Indexation Getting Familiar With lambda Functions Expanding Functionality of the .iloc[] Attribute

2. Dealing With Conditions

Setting Condition Selecting Data Based on Condition Dealing With Several Conditions Making Your Code Beautiful Conditions Quiz

3. Extracting Data

Is Data in ...?Combining Your Knowledge Between Method Extracting Specific Data Finding the Smallest Values of a Column Finding the Largest Values of a Column Finding the Correlation

4. Aggregating Data

Getting Familiar With the .groupby() Method Grouping by Several Columns Complicated Grouping Advanced Grouping Dealing With Pivot Tables Creating a Pivot Table

5. Preprocessing Data

Checking for Missing Values Calculating the Number of Missing Values What Will We Do With the NaN Values?How to Delete Only NaN Values?Filling In the Missing Values Managing Categorical Variables Checking the Column Type Managing an Incorrect Column Renaming the Column

Filling In the Missing Values

Deleting missing values is not the only way to get rid of them. You can also replace all NaNs with a defined value, for instance, with the mean value of the column or with zeros. It can be useful in a lot of cases. You will learn this in the course Learning Statistics with Python.

Look at the example of filling missing values in the column 'Age' with the median value of this column:


              1234
            
import pandas as pd
data = pd.read_csv('https://codefinity-content-media.s3.eu-west-1.amazonaws.com/4bf24830-59ba-4418-969b-aaf8117d522e/titanic_2', index_col = 0)
data['Age'].fillna(value=data['Age'].median(), inplace=True)
print(data['Age'].isna().sum())

Explanation:

value = data['Age'].median() - using the argument value, we tell the .fillna() method what to do with the NaN values. In this case, we applied the .fillna() method to the column 'Age' and replaced all missing values with the median of the column;
inplace=True - the argument we can use for saving changes.

Task

One of the most common ways of filling missing values is replacing them with the mean value of the column. So, your task here is to replace the NaN values in the column 'Age' with the mean value of the column (using the inplace = True argument). Then output the sum of the missing value in the column 'Age'.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

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Section 5. Chapter 5

Filling In the Missing Values

Look at the example of filling missing values in the column 'Age' with the median value of this column:


              1234
            
import pandas as pd
data = pd.read_csv('https://codefinity-content-media.s3.eu-west-1.amazonaws.com/4bf24830-59ba-4418-969b-aaf8117d522e/titanic_2', index_col = 0)
data['Age'].fillna(value=data['Age'].median(), inplace=True)
print(data['Age'].isna().sum())

Explanation:

value = data['Age'].median() - using the argument value, we tell the .fillna() method what to do with the NaN values. In this case, we applied the .fillna() method to the column 'Age' and replaced all missing values with the median of the column;
inplace=True - the argument we can use for saving changes.

Task

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 5. Chapter 5

Filling In the Missing Values

Look at the example of filling missing values in the column 'Age' with the median value of this column:


              1234
            
import pandas as pd
data = pd.read_csv('https://codefinity-content-media.s3.eu-west-1.amazonaws.com/4bf24830-59ba-4418-969b-aaf8117d522e/titanic_2', index_col = 0)
data['Age'].fillna(value=data['Age'].median(), inplace=True)
print(data['Age'].isna().sum())

Explanation:

value = data['Age'].median() - using the argument value, we tell the .fillna() method what to do with the NaN values. In this case, we applied the .fillna() method to the column 'Age' and replaced all missing values with the median of the column;
inplace=True - the argument we can use for saving changes.

Task

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Look at the example of filling missing values in the column 'Age' with the median value of this column:


              1234
            
import pandas as pd
data = pd.read_csv('https://codefinity-content-media.s3.eu-west-1.amazonaws.com/4bf24830-59ba-4418-969b-aaf8117d522e/titanic_2', index_col = 0)
data['Age'].fillna(value=data['Age'].median(), inplace=True)
print(data['Age'].isna().sum())

Explanation:

value = data['Age'].median() - using the argument value, we tell the .fillna() method what to do with the NaN values. In this case, we applied the .fillna() method to the column 'Age' and replaced all missing values with the median of the column;
inplace=True - the argument we can use for saving changes.

Task

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Section 5. Chapter 5

Switch to desktop for real-world practiceContinue from where you are using one of the options below