Python datastrukturer

Hva

Du kan kopiere kodeeksemplene inn i moduler og eksperimentere med dem.

List

Programmet setter opp en enkel liste og skriver ut innholdet.

"""
Simple module demonstrating lists and loops
"""
S=['ole','adam','marit','silvio','petronella']
# dump it
print(S)
# simplest
for name in S:
    print (name)
# for loop
for ix in range(0,len(S)):
    print (S[ix])
#while loop
ix=0
while ix < len(S):
    print (S[ix])
    ix+=1

Lister og sortering.

"""
Simple module demonstrating lists and sorting
"""
S=['ole','adam','marit','silvio','petronella']
for name in S:
    print(name)
print ('------ reversed -------')
S.reverse()
for name in S:
    print(name)
print ('--- sorted -----')
S.sort()
for name in S:
    print(name)
print ('---- sorted and then reversed ---')
S.reverse()
for name in S:
    print(name)

Lister av lister, og sortering.

"""
Simple module demonstrating lists and sorting
name and year of birth
"""
import datetime
S=[['ole',1998],['adam',2002],['marit',1973],['silvio',2002],['petronella',1956]]
# dump it
for person in S:
    print(person)
# sort sets as they are
S.sort()
for person in S:
    print(person)
# sort on age
def yearOfBirthKey(a):
    return a[1]
S.sort(key=yearOfBirthKey)
y=datetime.datetime.today().year
for person in S:
    print (person[0]+' is '+str(y-person[1])+' years old')

Dictionary

"""
Working with dictionaries
"""
import datetime
D={}
D['alex']=['mysen',1998]
D['jens']=['halden',2005]
D['peder']=['moss',2001]

print('-------------  dump ------------')
print(D)

print('-------------  loop ------------')
keylist=D.keys()
for k in keylist:
    print (k,' is from ',D[k][0],
           ' and is born in ',str(D[k][1]))

print('-------------  sort on name ------------')
keylist=sorted(D)
for k in keylist:
    print (k,' is from ',D[k][0],
           ' and is born in ',str(D[k][1]))

print('-------------  sort decending on age ------------')
y=datetime.datetime.today().year
def yearOfBirthKey(a):
    return a[1][1]
items=D.items()
mitems=sorted(items,key=yearOfBirthKey)
for item in mitems:
    print (item[0],' is ',str(y-D[item[0]][1]),
           ' years old, from ',D[item[0]][0])

print('-------------  sort ascending on age ------------')
y=datetime.datetime.today().year
def yearOfBirthKey1(a):
    return -a[1][1]
items=D.items()
mitems=sorted(items,key=yearOfBirthKey1)
for item in mitems:
    print (item[0],' is ',str(y-D[item[0]][1]),
           ' years old, from ',D[item[0]][0])

Tuple

Tuples er i korthet lister som ikke kan endres.

# tuples
t=("ole","jens","per")
print(t)
def collectThem(t1,t2):
    return t1+t2
all=collectThem(("a","b"),("c","d"))
print (all)