Data Science with Python Certification Cheat Sheet 2026

The 30 highest-yield Data Science with Python Certification facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which forecasting model captures both trend and seasonality using exponential smoothing? → Holt-Winters model
2. Which statistical method measures the linear relationship strength between two continuous variables? → Pearson correlation coefficient
3. What is a confidence interval in statistics? → A range likely to contain the true population parameter
4. Which Python function calculates the standard error of the mean? → scipy.stats.sem()
5. In spaCy, what attribute of a `Token` object returns its part-of-speech tag? → token.pos_
6. What does Python's "capture" cell magic command not support? → It cannot be used to capture graphical cell output
7. What does the PACF (Partial Autocorrelation Function) help determine in ARIMA modeling? → The AR (p) order
8. Choose a non-indexed object. → None of these
9. What does the following Python code produce? a, b = 0, 1 while b print(b, end=' '); a, b = b, a+b → 1 1 2 3 5 8 1 3
10. Which Python library provides pre-trained Word2Vec and FastText models for loading and using word embeddings? → Gensim
11. Which Python library provides the `word_tokenize()` function for splitting text into individual tokens? → NLTK
12. What is a bigram in NLP? → A sequence of two consecutive words used as a single feature
13. What is statistical power in hypothesis testing? → The probability of correctly rejecting a false null hypothesis
14. Which scikit-learn class converts a collection of text documents to a matrix of TF-IDF features? → TfidfVectorizer
15. What does a p-value less than 0.05 typically indicate in hypothesis testing? → There is strong evidence to reject the null hypothesis
16. What does the Jupyter Notebook application not apply to? → Cell may only be run one at a time
17. Which measure of central tendency is most resistant to outliers? → Median
18. Which of the following is a key assumption of Linear Regression that, if violated, can lead to unreliable and biased coefficient estimates? → The residuals (error terms) are independent of each other.
19. What serves as the fundamental building block for all sparse indexed data structures? → SparseArray
20. Which Python library provides ARIMA and SARIMA models for time series forecasting? → statsmodels
21. What are things like pandas? → NumPy
22. What is the primary objective of the Principal Component Analysis (PCA) algorithm? → To reduce the dimensionality of a dataset while preserving the maximum amount of variance.
23. What plot evaluates the unpredictability of time series? → Autocorrelation
24. Which of the following statements correctly describes the behavior of `np.hstack()`? → It stacks arrays in sequence horizontally (column-wise).
25. How do you parse a date column automatically when reading a CSV file with pandas? → pd.read_csv(file, parse_dates=['date'])
26. Which statistical test should you use to compare means across more than two groups? → ANOVA
27. What does `scipy.stats.mannwhitneyu()` test in Python? → Whether two independent samples come from the same distribution
28. What qualifies as not a property of an ndarray object? → length
29. Which method on a scikit-learn vectorizer both learns the vocabulary and transforms the training data in one step? → fit_transform()
30. What kind of data can be used with Pandas? → All of these