At this stage, we have only a raw text representing reviews, which is not sufficient to run any machine learning algorithm. We need to transform the text into a numeric format, aka perform the so-called "feature extraction" (it is as it sounds; we are taking the input data and extracting features which we will use to train a model). The method generates some new features based on input feature(s). There are many methods regarding how the text can be transformed into numeric features. We can count the number of words, length of text, or number of punctuations. However, to represent text in a systematic way that would reflect a text structure, we need more elaborate methods.
Germany
Slovakia
Canada
Brazil
Singapore
Hungary
Philippines
Mexico
Thailand
Ukraine
Luxembourg
Estonia
Lithuania
Norway
Chile
United States
Great Britain
India
Spain
South Korea
Ecuador
Colombia
Taiwan
Switzerland
Indonesia
Cyprus
Denmark
Finland
Poland
Malta
Czechia
New Zealand
Austria
Turkey
France
Sweden
Italy
Egypt
Belgium
Portugal
Slovenia
Ireland
Romania
Greece
Argentina
Malaysia
South Africa
Netherlands
Bulgaria
Latvia
Australia
Japan
Russia