CNM - C4

define darcy’s flow as a function

q = k*A*h/L

define, name, list args, new line with 4 spaces, function, new line, return output

give the code for calling this function if:

• k = 0.3

• A = 5.2

• h = 1.7

• L = 0.3

what do you have to use to get flow rate as an array from this function

a for loop and args as arrays

how do you use a keyword argument in a function - modify this code as an example

what is the difference between variables defined inside and outside a function

Scope

• variables defined inside a function are in the local scope and can’t be accessed outside of it

• variables defined outside of a function have global scope and can be accessed anywhere

so should have dif names

what is pandas

• a module like numpy is

• a module that allows us to work with tables of data

• used for stats, graphs, etc

• import pandas as pd

what is a dataframe

• a dataframe is to pandas what an array is to numpy

• dataframes hold more types of data than arrays

• can access data through labels rather than position

• helpful with time series data

what dataframe would this code produce

how to pull this section of the dataframe df

df.loc — meaning locate

line of code to import data from a file

how do you add a new column to a dataframe

eg a new column which sums the x column value and y column value in each row and multiplies this by 2

line of code to apply the function to the dataframe

this is a dataframe of the rainfall and other values in tyne

what is a line of code to plot the precipitaion in tyne from 01/01/1999 to 01/02/1999

What is a module in Python and how can you create your own?

A module is a separate file containing extra functionality, that you can create by saving a script with functions as a .py file and importing it

What is a file mode in Python, name 4 types and what they do

A file mode tells Python how a file should be opened and what operations are allowed.

"r" – Read only

"r+" – Read and write

"w" – Write only (deletes current content)

"a" – Append (keep current content and add to it)

open("file.txt", mode) - how to use - insert one of the above as ‘mode’

What does the following code do?

file = open("open_me.txt", "w")

file.write("Hello")

file.close()

Replaces the contents of open_me.txt with "Hello"

Why do we use a while loop in this code instead of a for loop?

Because for loops cannot calculate change