Test 1 Flashcards

Question

Dictionaries

Answer 1

Similar to list, as can store multiple items in a single variable, but also allows to store "keys" with each paired item. Must specify pairs of "keys" and "values". Defined with {}

Answer 2

-Cannot start with a number -Cannot use a reserved word as a name (eg. And, def, else, if, while, return) -Cannot use special symbols -Do read upper and lowercase characters differently

Answer 3

- Never use the letters I or O as single letter names (easily mistaken for 1 and 0) -Don’t make them too general, but also not so descriptive that they become wordy -Keep them short, but long enough to be descriptive -Variable names should be lowercase with underscores used as a separator accel_x = 1.06 force_z = 10.25 A constant (value that will remain unchanged) can be fully capitalized GRAVITY = 9.81

Answer 4

Blocks of code that analyze variables and decide the direction the program takes. When developing control structures, we need to have an understanding of what is coming in and what is going out.

Answer 5

State of the variables entering control structure

Answer 6

the program or algorithm that runs based on the preconditions

Answer 7

state of the variables after the control structure has run

Answer 8

simply run 1 line after another like a recipe. Most basic form of control structure. Require you to define a step by step process required to complete a task.

Answer 9

allows for decisions and branching to occur within the block of code (eg if/else statements- most common). A block of code used to determine which steps should be completed based on the input variable/precondition. By doing this we enable to program to make a decision and alter the flow of control- can be binary sections (true (1) vs false (0)) or multi-way selections. * be conscious of indenting

Answer 10

used for creating (iterating or looping) lines of code (eg. For loop). Block of code that can be repeated (iterated) a certain number of times (or until a specific condition is met). Most common- loop. Python- loop iterates over the items in a variable or can generate a sequence of numbers using the "range" function. "range" can be used in place of a previously defined list and allows us to define the set of numbers we want the loop to iterate over. Can manipulate the specific values we want to loop over. Variable "message" above the loop allows to add iteratively. Create a temporary variable using the "temp"- can combine the strong info using "+". Can save new string into the variable created "message" using the ".append" variable- if don’t use .append the temp string variable would get written over during each iteration of the loop.

Answer 11

A block of organized and reusable code that will only run when you call it. Can send it some data (or parameters) and it will run the code, then output something in return. Many functions are built into python. -abs()- returns the abs value of a number -len()- returns the length of an object -max()- returns the largest item in an object -min()- returns the smallest item in an object -round()- rounds a number -sum()- sums the items of a list Some require only one input and return only one output, many times need to enter multiple inputs and/or it can return multiple outputs.

Answer 12

1. Type "def" to tell python we want to create a definition of a function 2. Type the name you want the function to be called- be strategic in choice, cant use the same name as a built in 3. Use () to define the input for the function (general name to be used within the function). Depending on the function may have no input, 1 input, or many inputs 4. Close the definitions line with a colon Can now define the body of the function that will do the work on the input variable when it is called. Note that this entire body of the function must be indented in python code

Answer 13

-use # to comment code

Answer 14

-Write meaningful comments that summarize block of code, overall processes, or areas that may be unclear or confusing. -Keep them short and to the point -Do not simply reiterate the code. -We can directly reference processing methods or code as a citation or external link in a comment. -Comments can also be used to list author, date, and other information on the code. -Documentation strings specialized forms of comments that use three double quotes to open and close your comment and are used to describe the function.

Answer 15

Any information that has been translated into something that we can move, process, visualize, ect. Data- is plural. Storing into in lists and dictionaries can be good way to manage certain types o data- however these varaibles can be limiting when looking to examine larger sets of data.

Answer 16

Used to store larger data. More efficient storage than list variable and allows more efficient operations/processing. 2D arrays allow storage of larger sets of data in a variable with rows and columns

Answer 17

Large open source library for working woth large arrays and matrices. Allows the creation of array objects, rather than simple arrays. These objects are easier to use and manipulate, and faster computationally. Foundational library for which almost all other data science libraries and functions are built. Does not come standard with Python but is included in Anaconda. Import numpy as np is primarily used for arrays Note: use () as the base definition for functions, but will often use square brackets inside to separate numbers.

Answer 18

Can do many things with arrays of numbers including math (+, -, *, /) NumPy is primarily used for arrays of numbers but can handle other types of data (eg strings, booleans, ect) as long as they are not mixed in the same array

Answer 19

Important when working woth arrays is to be able to index specific elements of data and/or find certain values in an array. Important: When indexing in python use (), and always make sure you are using the correct brackets. To index data, identify the specific element in the array we want, using the [row, col] notation. -Additionally, if we want all values in specific row or column, we can do so by using : rather than a number to signify all numbers. -Could also put a series of numbers to represent a subset of data for a row or column. -Could also index data in an array using comparators or Booleans- generate a Booleans separately and use it to choose specific indices in the data or build it right into the index itself. Ie syntax print(A(>1)) would only print elements where the values was greater than 1.

Answer 20

A data analysis library in python that builds additonal functionality into the NumPy library. Pandas allow us to combine numbers, strings, Booleans, ect all in the same array if we want. We can also have headers for our columns to make it easier to read data. Panda allows for a cleaner application we need to have a variety of data to work with.

Answer 21

Can index using the "loc" and "iloc" functions. These methods can select data based on the specific row of data ("loc") or the index value ("iloc"). Most of the time they are the same since the index order is in the correct sequence.

Answer 22

Used to be the append feature, now use "concat"- this function will look to combine two DataFrames (concatentate-joining together in series)- making new DataFrame?

Answer 23

When working with data, normally expect each observation as a row and each column as a variable. *** confused To import data from a .csv file we simply need to use the function pd.read_csv with the name of the file.

Answer 24

Matplotlib offers many different kinds of plots. Use the ".plot" command with x and y data. Define X and Y variables as well as axis titles.

Test 1 Flashcards

(48 cards)