list
One data type built into Python is a list: list. A list is an ordered collection from which elements can be added and removed at any time.
Code:
print('------------------------------------------------------')
#list
classmates = ['Michael','Bob','Tracy','Jason']
print(classmates)
print('classmates =',len(classmates)) #Get the length of the array
print(classmates[0]) #The first element
print(classmates[1]) #The second element
print(classmates[2]) #The third element
print('------------------------------------------------------')
print(classmates[-1]) #The last element
print(classmates[-2]) #The penultimate element
print(classmates[-3]) #The third last element
print('------------------------------------------------------')
a = len(classmates)-1 # index of last element
print(classmates[a]) # Equivalent to print(classmates[-1])
print('------------------------------------------------------')
print(classmates)
print(classmates[-1])
classmates.append('adm') #Insert an element at the end
print(classmates)
print(classmates[-1])
print('------------------------------------------------------')
print(classmates)
print(classmates[1])
classmates.insert(1,'Plada') #Insert an element at the specified position
print(classmates)
print(classmates[1])
print('------------------------------------------------------')
print(classmates.pop()) #delete the element at the end of the list
print(classmates)
print('------------------------------------------------------')
print(classmates)
print('classmates.pop(-1) :',classmates.pop(-1)) #Delete the element at the specified position
print(classmates)
print('classmates.pop(1) :',classmates.pop(1))
print(classmates)
print('------------------------------------------------------')
print(classmates)
a = classmates[1] = 'Jason'
print('classmates[1] =',a)
print(classmates)
print('------------------------------------------------------')
L = ['abc',123,True]
print (len (L))
print(L[0])
print(L[1])
print(L[2])
print('------------------------------------------------------')
s = ['python','java',['asp','php'],'c++']
p = ['asp','php']
s = ['python','java',p,'c++'] #two-dimensional array
print('p =',p)
print('s =',s)
print('p[1] =',p[1])
print('s[2][1] =',s[2][1])
print('------------------------------------------------------')
a = ['abcd','efg','hijk']
b = [a,'lmn','opq']
c = [b,'rst','uvw','xyz'] #Three-digit array
print('c =',c)
print('a[0] =',a[0])
print('b[0][0] =',b[0][0])
print('c[0][0][0] =',c[0][0][0])
print('------------------------------------------------------')
L = []
print ('L =', len (L))
tuple
Another type of ordered list is called a tuple: tuple. Tuple and list are very similar, but once tuple is initialized, it cannot be modified. For example, it also lists the names of classmates:
Code:
print('------------------------------------------------------')
#tuple: Once initialized it cannot be modified
classmates = ('Michael','Bob','Tracy','Jason')
print('classmates =',classmates)
t = (1,2)
print('t =',t)
r = ('a',)
print('r =',r)
print('------------------------------------------------------')
x = ('a','b',['A','B'])
print('x =',x)
x[2][0] = 'X'
x[2][1] = 'Y'
print('x =',x)
print('------------------------------------------------------')
x = ('a','b',('A','B'))
print('x =',x)
x[2][0] = 'X' #tuple array cannot be modified, an error will be reported
x[2][1] = 'Y'
print('x =',x)
TestCode:
# -*- coding: utf-8 -*- L = [ ['Apple','Google','Microsoft'], ['Java','Python','Ruby','PHP'], ['Adam','Bart','Lisa'] ] #print Apple: print(L[0][0]) #Print Python: print(L[1][1]) #Print Lisa: print(L[2][2])
