Categorische data omzetten en analyseren

Exploratory Data Analysis in Python

George Boorman

Curriculum Manager, DataCamp

De data bekijken

print(salaries.select_dtypes("object").head())

  Designation                 Experience    Employment_Status    Employee_Location    Company_Size
0 Data Scientist              Mid           FT                   DE                   L
1 Machine Learning Scientist  Senior        FT                   JP                   S
2 Big Data Engineer           Senior        FT                   GB                   M
3 Product Data Analyst        Mid           FT                   HN                   S
4 Machine Learning Engineer   Senior        FT                   US                   L

Functietitels

print(salaries["Designation"].value_counts())

Data Scientist                              143
Data Engineer                               132
Data Analyst                                 97
Machine Learning Engineer                    41
Research Scientist                           16
Data Science Manager                         12
Data Architect                               11
Big Data Engineer                             8
Machine Learning Scientist                    8
...

Functietitels

print(salaries["Designation"].nunique())

Functietitels

Staafdiagram met de vijf populairste datarollen: data scientist, data engineer, data analyst, machine learning engineer en research scientist

Waarde halen uit categorieën

Huidige formaat beperkt onze inzichten
pandas.Series.str.contains()
- Zoek in een kolom naar één of meerdere strings

salaries["Designation"].str.contains("Scientist")

0       True
1       True
2      False
3      False
       ...  
604    False
605    False
606     True
Name: Designation, Length: 607, dtype: bool

Meerdere zinsdelen in strings vinden

Woorden van interesse: Machine Learning of AI

salaries["Designation"].str.contains("Machine Learning|AI")

0      False
1       True
2      False
3      False
       ...  
604    False
605    False
606     True
Name: Designation, Length: 607, dtype: bool

Meerdere zinsdelen in strings vinden

Woorden van interesse: Alles dat begint met Data

salaries["Designation"].str.contains("^Data")

0       True
1      False
2      False
3      False
       ...  
604     True
605     True
606    False
Name: Designation, Length: 607, dtype: bool

Meerdere zinsdelen in strings vinden

job_categories = ["Data Science", "Data Analytics", 
                  "Data Engineering", "Machine Learning",
                  "Managerial", "Consultant"]

Meerdere zinsdelen in strings vinden

data_science = "Data Scientist|NLP"

data_analyst = "Analyst|Analytics"

data_engineer = "Data Engineer|ETL|Architect|Infrastructure"

ml_engineer = "Machine Learning|ML|Big Data|AI"

manager = "Manager|Head|Director|Lead|Principal|Staff"

consultant = "Consultant|Freelance"

Meerdere zinsdelen in strings vinden

conditions = [
    (salaries["Designation"].str.contains(data_science)),

    (salaries["Designation"].str.contains(data_analyst)),

    (salaries["Designation"].str.contains(data_engineer)),

    (salaries["Designation"].str.contains(ml_engineer)),

    (salaries["Designation"].str.contains(manager)),

    (salaries["Designation"].str.contains(consultant))
]

De categorische kolom maken

salaries["Job_Category"] =

De categorische kolom maken

salaries["Job_Category"] = np.select(conditions,

De categorische kolom maken

salaries["Job_Category"] = np.select(conditions, 
                                     job_categories,

De categorische kolom maken

salaries["Job_Category"] = np.select(conditions, 
                                     job_categories, 
                                     default="Other")

Voorbeeld van functiecategorieën

print(salaries[["Designation", "Job_Category"]].head())

                  Designation      Job_Category
0              Data Scientist      Data Science
1  Machine Learning Scientist  Machine Learning
2           Big Data Engineer  Data Engineering
3        Product Data Analyst    Data Analytics
4   Machine Learning Engineer  Machine Learning

Frequentie van functiecategorieën visualiseren

sns.countplot(data=salaries, x="Job_Category")

plt.show()

Staafdiagram met het aantal banen per categorie

Laten we oefenen!

Exploratory Data Analysis in Python