Create a list
Simple list
mylist = [“apple”, “orange”, “banana”, “mango”, “pineapple”]
mylist[2] # returns ‘banana’
mylist[-1] # returns ‘pineapple’
mylist[2:4] #returns ‘banana’, ‘mango’, ‘pineapple
if “apple” in thislist:
  print(“Yes, ‘apple’ is in the fruits list”)
mylist.insert(2, “watermelon”) #insert at position speified
mylist.append(‘grapes’) #adds to end of list
mylist = [“apple”, “banana”, “cherry”]
tropical = [“mango”, “pineapple”, “papaya”]
mylist.extend(tropical) # adds tropical list to thislist
my.remove(“banana”) #removes first occurrence
mylist.pop(1) #removes specified instance
del mylist[0] #also removes instance
del mylist # deletes list
clear(mylist) # clears the list

for i in thislist: #look list
  print(i)

i = 0
while i < len(thislist): #while loop
  print(thislist[i])
  i = i + 1

newlist = []
for x in fruits: #adds list items containing a to new list
  if “a” in x:
    newlist.append(x)

thislist.sort() #sort alphabetically or numerically depending on data type
thislist.sort(reverse = True) #sort in reverse
thislist.sort(key = str.lower) #sort lower case first
thislist.reverse() #sort in reverse
mylist = thislist.copy() #copy list
mylist = list(thislist) #also makes a list
list3 = list1 + list2 #concetenate lists

6 rows, 2 columns

b1 = [[2308, 6], [2408, 6.2], [2508, 5.8],[2608, 5.6], [2708, 5.9]] #create the list
print(b1) #print the list
print(len(b1)) #print length  of list
print(type(b1)) #print data type of list
print(b1[:2]) #print the first 2 elements in the list (note doesn’t use zero)
print(b1[3:]) #print from the 3rd elements and after

Reference Index in array

b1[3] #returns second element
b1[0:2] # returns first and second element of list
b1[-1] # returns last element index

Add and Delete, Update
Delete
del(b1[0]) # delete first element
or
b1.pop(1) #remove second element


Insert
b1.insert(1,[24082, 111]) #insert element at position 1
Update
b1[6]= [2808,6.7] #update value

Append
Additions = [[29008, 6.6], [3008, 6], [3108, 6.1]]
b1.extend(Additions) #Adds the Additions list to b1
b1.append([2808,6.6]) # add 1 element (only 1)

Clear the list
b1.clear() #empties the list

Check if element in array
if [2308,6.2] in b1: print(“yes”)
Loop
for x in b1: print(x)

def country_select(countrylist):
count = 1
for i in countrylist:
print(f”{i}: {countrylist[i]}”)
count = count + 1
return countrylist

Numpy

baseball = [180, 215, 210, 210, 188, 176, 209, 200]
import numpy as np
np_baseball = np.array(baseball)
print(type(np_baseball))
mean = np_baseball.mean()
print(“mean is: “+ str(mean))
med = np.median(np_baseball)
print(“median is: “+str(med))
std = np.std(np_baseball)
print(“standard deviation is: “+str(std))