Classify URLs

[boring_accountant]

Hi again,

A variable is just a name to which you can assign values or other objects. df_filtered is a variable of type pandas.DataFrame.

As to the issue at hand, df_filtered appears to me like it should be defined. I ran a quick test at home and didn't get the error message you are obtaining:

import pandas as pd
# Setting up the mock dataframe
df = pd.DataFrame({
    'Destination': ['website.com/test1', 'www.website.com/test2', 'www.somethingelse.com'], 
    'Source': ['website.com/string1', 'website.com/string2', 'website.com/somethingelse'], 
    'Type': ['AHREF', 'AHREF', 'AHREF']
})

# Simplifying your code to filter the DataFrame
# Note that the change from df[] to df.loc[] is to prevent some
# issues you needn't worry about right now
# If you do want, you can look it up here:  
# http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
df_filtered = df.loc[(df.Destination.str.contains("website.com")) & 
    (df.Source.str.contains("website.com")) & 
    (df.Type == "AHREF"), :]

def categories(Source):
    if '/string1' in Source: return 'Category 1'
    elif '/string2' in Source: return 'Category 2'
    else: return 'other'

df_filtered.loc[:, 'Category'] = df_filtered.Source.apply(categories)
print(df_filtered)

Output:
             Destination               Source   Type   Category
0      website.com/test1  website.com/string1  AHREF  Category1
1  www.website.com/test2  website.com/string2  AHREF  Category2

Did you run all of your code in consecutively, in the order shown in your post ? If you copy and paste my code in this current post, do you get the same error message ?

---

As for your other question on remembering how to complete some of those tasks, I personally learned by practicing a lot. Follow some tutorials / books, try the codes yourself, play with them, modify them, etc. Try to read the documentation on some libraries you find interesting. You'll learn about functions you may need but didn't know existed or maybe you'll just keep in the back of your head that function xyz exists and can be used in scenario abc.

Cheers