Free Interactive Flashcards

Tuckman's model: Forming (team assembly), Storming (conflict and competition), Norming (agreement and consensus), Performing (productive and effective), Adjourning (task completion and dissolution).

Servant leadership puts the needs of team members first, helping them develop and perform at their highest potential. The leader serves the team by removing obstacles and providing support.

The Project Management Triangle (or Triple Constraint) consists of Scope, Time, and Cost. These three constraints are interdependent - changing one affects the others. Quality sits at the center of this triangle.

A risk register is a document containing results of risk analysis and risk response planning. It includes identified risks, risk owners, probability, impact, risk responses, and status.

The four strategies are: Exploit (ensure opportunity occurs), Share (allocate ownership to best capture benefit), Enhance (increase probability or impact), and Accept (willing to take advantage if it occurs).

The four strategies are: Avoid (eliminate the threat), Transfer (shift impact to third party), Mitigate (reduce probability or impact), and Accept (acknowledge without proactive action).

Lead is the amount of time a successor activity can be advanced (start earlier). Lag is a delay before the successor activity can begin. Both are used in schedule network analysis.

EVM integrates scope, schedule, and cost to measure project performance. Key metrics: PV (Planned Value), EV (Earned Value), AC (Actual Cost), SPI (Schedule Performance Index), CPI (Cost Performance Index).

CPM is a technique to identify the longest sequence of dependent activities (critical path) and determine the minimum project duration. Activities on the critical path have zero float.

A WBS is a hierarchical decomposition of the total scope of work into manageable components. It organizes and defines the total scope, with each level representing increasingly detailed definitions.

Scrum uses fixed-length sprints with defined roles and ceremonies. Kanban is a continuous flow system with work-in-progress limits, no prescribed roles, and changes can happen anytime.

The three roles are: Product Owner (defines features and priorities), Scrum Master (facilitates process and removes impediments), and Development Team (self-organizing group that delivers the increment).

A Sprint is a time-boxed iteration (typically 2-4 weeks) during which a potentially releasable product increment is created. Each Sprint has a goal and contains planning, daily standups, development, review, and retrospective.

1. Individuals and interactions over processes and tools 2. Working software over comprehensive documentation 3. Customer collaboration over contract negotiation 4. Responding to change over following a plan

Scope Management includes processes to ensure the project includes all work required, and only the work required, to complete the project successfully. It covers both product and project scope.

Integration Management includes processes to identify, define, combine, unify, and coordinate various processes and activities within the Project Management Process Groups.

1. Integration Management 2. Scope Management 3. Schedule Management 4. Cost Management 5. Quality Management 6. Resource Management 7. Communications Management 8. Risk Management 9. Procurement Management 10. Stakeholder Management

Closing finalizes all activities across all process groups to formally complete the project or phase, including final deliverable acceptance, lessons learned, and resource release.

Initiating includes defining a new project or phase, obtaining authorization to start, identifying stakeholders, and developing the project charter.

The five Process Groups are: 1. Initiating 2. Planning 3. Executing 4. Monitoring and Controlling 5. Closing

Class methods (@classmethod) receive the class as first argument and can modify class state. Static methods (@staticmethod) don't receive implicit first argument and can't modify class or instance state.

__new__ creates and returns a new instance (called first). __init__ initializes the instance after it's created (called second). __new__ is rarely overridden except for immutable types.

The four pillars are: Encapsulation (bundling data and methods), Inheritance (creating new classes from existing ones), Polymorphism (same interface for different types), and Abstraction (hiding complex details).

pyplot provides a MATLAB-like interface for quick plotting. The object-oriented API gives more control and is better for complex plots, using figure and axes objects explicitly.

Matplotlib is a comprehensive plotting library for creating static, animated, and interactive visualizations in Python. It's the foundation for many other plotting libraries.

Vectorization is performing operations on entire arrays instead of individual elements using loops. It's much faster because operations are pushed to optimized C code.

A NumPy array (ndarray) is a fast, flexible container for large datasets. It's a grid of values of the same type, indexed by a tuple of integers.

Broadcasting is NumPy's method of performing arithmetic operations on arrays of different shapes. It allows operations between a scalar and an array, or between arrays of different shapes, without explicitly replicating data.

merge() combines DataFrames based on common columns or indices (similar to SQL joins). join() is a convenience method that merges on indices by default. merge() is more flexible.

Common methods: dropna() removes rows/columns with missing values, fillna() fills missing values with specified value, interpolate() fills using interpolation.

groupby() splits data into groups based on one or more columns, applies a function to each group independently, and combines the results. It's used for aggregation and transformation.

loc is label-based indexing (uses row/column names). iloc is integer position-based indexing (uses numeric indices starting from 0).

A DataFrame is a 2-dimensional labeled data structure with columns of potentially different types. It's similar to a spreadsheet or SQL table and is the most commonly used pandas object.

== checks if values are equal (value equality). 'is' checks if two variables refer to the same object in memory (identity equality).

The 'with' statement ensures proper acquisition and release of resources, particularly file handles. It automatically calls cleanup code, even if an exception occurs.

List comprehension provides a concise way to create lists. Syntax: [expression for item in iterable if condition]. Example: [x**2 for x in range(10) if x % 2 == 0]

Set is mutable and can be modified after creation. Frozenset is immutable and cannot be changed. Frozensets can be used as dictionary keys or elements of other sets.

A dictionary is a collection of key-value pairs, enclosed in curly braces {}. Keys must be unique and immutable. Example: {'name': 'John', 'age': 30}

Lists are mutable (can be changed after creation) and use square brackets []. Tuples are immutable (cannot be changed) and use parentheses (). Tuples are generally faster and use less memory.

The main built-in data types are: int, float, str, bool, list, tuple, dict, set, and NoneType.

Decorators are functions that modify the behavior of other functions. They use the @decorator syntax and are commonly used for logging, authentication, and caching.

A lambda function is an anonymous, inline function defined with the lambda keyword. Syntax: lambda arguments: expression. Example: square = lambda x: x**2

Python uses indentation (whitespace) to define code blocks instead of braces. Consistent indentation (typically 4 spaces) is required for proper syntax.

Use the 'def' keyword: def function_name(parameters): # function body return value

COMMIT saves all changes made in the current transaction permanently. ROLLBACK undoes all changes made in the current transaction, reverting to the previous state.

A transaction is a sequence of SQL operations treated as a single unit of work. It follows ACID properties: Atomicity, Consistency, Isolation, and Durability.

The main DML (Data Manipulation Language) commands are: SELECT (retrieve data), INSERT (add new rows), UPDATE (modify existing rows), and DELETE (remove rows).

A query execution plan shows how the database engine will execute a query, including index usage, join methods, and estimated costs. It's used for performance tuning.

A clustered index determines the physical order of data in a table (one per table). A non-clustered index creates a separate structure that points to the data (multiple allowed per table).

An index is a database structure that improves the speed of data retrieval operations on a table at the cost of additional storage space and slower write operations.

LAG() accesses data from a previous row in the same result set without a self-join. LEAD() accesses data from a subsequent row. Both are useful for comparing values across rows.

PARTITION BY divides the result set into partitions (groups) and applies the window function separately to each partition, similar to GROUP BY but without collapsing rows.

ROW_NUMBER() assigns unique sequential numbers. RANK() assigns ranks with gaps after ties. DENSE_RANK() assigns ranks without gaps. Example: values 10,10,20 give ROW_NUMBER 1,2,3; RANK 1,1,3; DENSE_RANK 1,1,2.

ROW_NUMBER() assigns a unique sequential integer to rows within a partition of a result set, starting at 1 for the first row in each partition.

A recursive CTE references itself to process hierarchical data. It has two parts: an anchor member (base case) and a recursive member that references the CTE itself.

CTEs improve readability, allow recursive queries, can be referenced multiple times in the same query, and make complex queries easier to maintain and debug.

A CTE is a temporary named result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE statement. It's defined using the WITH clause and exists only during query execution.

RIGHT JOIN returns all rows from the right table and matching rows from the left table, with NULL for non-matching left table rows. It's the opposite of LEFT JOIN.

A self-join is when a table is joined with itself, typically used to compare rows within the same table or to create hierarchical relationships.

CROSS JOIN returns the Cartesian product of two tables, combining each row from the first table with every row from the second table.

INNER JOIN returns only matching rows from both tables. LEFT JOIN returns all rows from the left table and matching rows from the right table, with NULL for non-matching right table rows.

IN allows you to specify multiple values in a WHERE clause. It's a shorthand for multiple OR conditions. Example: WHERE country IN ('USA', 'Canada', 'Mexico')

LIKE is used for pattern matching with wildcards: % (any sequence of characters) and _ (single character). Example: WHERE name LIKE 'John%' finds names starting with John.

Common operators include: = (equal), <> or != (not equal), > (greater than), < (less than), >= (greater than or equal), <= (less than or equal), BETWEEN, IN, LIKE, IS NULL, AND, OR, NOT.

ORDER BY sorts the result set by one or more columns, either in ascending (ASC) or descending (DESC) order.

WHERE filters rows before grouping, while HAVING filters groups after aggregation. HAVING is used with GROUP BY for filtering aggregated results.

SELECT DISTINCT returns only unique values, removing duplicate rows from the result set.

SELECT column1, column2 FROM table_name WHERE condition ORDER BY column1;

Drill-through allows users to navigate from one report page to another with filtered context, enabling detailed analysis of specific data points.

Clustered bar charts display bars side-by-side for comparing multiple series, while stacked bar charts place bars on top of each other to show part-to-whole relationships.

A slicer is a visual filtering element that allows users to filter data across all visualizations on a page by selecting values from a list or range.

Use measures for aggregations and calculations that depend on user selections/filters. Use calculated columns when you need row-by-row calculations that don't change based on filters.

Context in DAX refers to the environment in which a formula is evaluated. There are two types: Filter Context (filters applied to the data) and Row Context (the current row being evaluated).

Measures are calculated at query time and don't take up storage space. They're evaluated based on filter context. Calculated Columns are computed during data refresh and stored in the model, evaluated row by row.

FILTER returns a table that represents a subset of another table based on a specified condition. It's used to create custom filters in DAX expressions.

ALL removes filters from a table or column, returning all rows regardless of filters. It's commonly used with CALCULATE to override existing filter context.

RELATED returns a related value from another table based on a relationship in the data model. It follows the many-to-one relationship direction.

SUM is an aggregation function that adds up values in a column, while SUMX is an iterator function that evaluates an expression for each row and then sums the results.

CALCULATE evaluates an expression in a modified filter context. It's one of the most important DAX functions, allowing you to change the context in which data is calculated.

Power BI can connect to various sources including Excel, SQL Server, Azure services, web APIs, SharePoint, Oracle, SAP, and many other databases and cloud services.

A gateway is a software that facilitates access to data in on-premises networks for Power BI service. It acts as a bridge between on-premises data sources and the cloud.

Import mode (data is imported and stored in the Power BI model) and DirectQuery mode (data remains in the source and is queried in real-time).

Power BI Desktop saves files with the .pbix extension, which contains the data model, visualizations, and queries.

Power Query is a data connectivity and data preparation technology that enables you to discover, connect, combine, and refine data across a wide variety of sources.

Power BI consists of three main components: Power BI Desktop (for creating reports), Power BI Service (cloud-based platform for sharing and collaboration), and Power BI Mobile (mobile apps for viewing reports).

Power BI is a business analytics service by Microsoft that provides interactive visualizations and business intelligence capabilities with an interface simple enough for end users to create their own reports and dashboards.