An analyst has two DataFrames: `customers` with columns `customer_id`, `name`, and `orders` with columns `order_id`, `customer_id`, `amount`. They need to create a DataFrame that includes all customer information along with their orders. Which operation should they use?

customers.append(orders, ignore_index=True)

orders.join(customers, on='customer_id')

pd.concat([customers, orders], axis=1)

pd.merge(customers, orders, on='customer_id')

A data analyst has two datasets: one with customer IDs and names, and another with customer IDs and purchase amounts. They want to create a single dataset with all columns. Which aggregation technique should they use?

Concatenating the datasets vertically

Merging the datasets on the customer ID column

Appending the datasets one after another

Grouping the datasets by purchase amount

An analyst is merging two DataFrames: `employees` with columns `emp_id`, `name`, `department` and `salaries` with columns `emp_id`, `salary`. They want to keep all employees, even those without a salary record. Which merge type should they use?

Outer merge: pd.merge(employees, salaries, on='emp_id', how='outer')

Inner merge: pd.merge(employees, salaries, on='emp_id', how='inner')

Right merge: pd.merge(employees, salaries, on='emp_id', how='right')

Left merge: pd.merge(employees, salaries, on='emp_id', how='left')

A healthcare researcher wants to study the long-term effects of a new drug. They need data from patient records over the past 10 years. The data already exists in hospital databases. Which data collection method should they use?

Internal data collection from the hospital's own records

Primary data collection through new clinical trials

Secondary data collection from existing hospital records

External data collection from public health databases

Python InstitutePCAD - Certified Associate in Data Analytics with Python

Domain 1Objective 1

Data Collection, Integration, and Storage PCAD-31 Practice Questions (Page 3)

Part of the Data Acquisition and Pre-Processing domain, which accounts for 29.2% of the PCAD-31 exam. Python Institute does not publish an official question count, but from its 60-minute exam (~25–40 total, ~7–7 in this domain), expect 2–2 from this objective — we provide 25 practice questions to prepare you well beyond it. (estimate)

25questions here

5free pages

6concepts

29.2%of the exam

Questions 11–15

11application · medium
An analyst has two DataFrames: `customers` with columns `customer_id`, `name`, and `orders` with columns `order_id`, `customer_id`, `amount`. They need to create a DataFrame that includes all customer information along with their orders. Which operation should they use?
Select an answer first
12foundation · easy
A data analyst has two datasets: one with customer IDs and names, and another with customer IDs and purchase amounts. They want to create a single dataset with all columns. Which aggregation technique should they use?
Select an answer first
13expert · hard
An analyst is merging two DataFrames: `employees` with columns `emp_id`, `name`, `department` and `salaries` with columns `emp_id`, `salary`. They want to keep all employees, even those without a salary record. Which merge type should they use?
Select an answer first
14application · medium
A healthcare researcher wants to study the long-term effects of a new drug. They need data from patient records over the past 10 years. The data already exists in hospital databases. Which data collection method should they use?
Select an answer first
15foundation · easy
A data analyst uses a publicly available government census dataset to analyze demographic trends. Which type of data collection method does this represent?
Select an answer first

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