九、给小白看的第二篇 Python 基础教程

l = [1, 2, 3]
print( l )# [1, 2, 3]
t = tuple(l)
print(t) # (1, 2, 3)
l = list(t)
print (l) #[1, 2, 3]

name = "Runsen"
age = 20
print( "Name: %s; Age: %d") % (name, age)
# Name: Runsen; Age: 20

t = (1, 2, 3, 1, 2, 3)
print (t.count(2) )# 2

t = (1, 2, 3, 1, 2, 3)
print( t.index(3) )# 2
try:
    print (t.index(4))
except ValueError as V:
    print(V)  # there is no 4 in tuple

d = {}
d["1"] = "one"
d["2"] = "two"
d["3"] = "three"
del d["3"]
for key, value in d.items():
    print ("%s --> %s" % (key, value))
#1 --> one
#2 --> two

d1 = {"1":"one", "2":"two"}
d1.clear()
print (d1 )# {}

d1 = {"1":"one", "2":"two"}
d2 = d1.copy()
print( d2 )#{'1': 'one', '2': 'two'}
print(d1 == d2) # True
print(d1 is d2) # False

l = [1, 2, 3]
t = (1, 2, 3)
d3 = {}.fromkeys(l)
print (d3) #{1: None, 2: None, 3: None}
d4 = {}.fromkeys(t, "default")
print(d4) #{1: 'default', 2: 'default', 3: 'default'}

d5 = {1:"one", 2:"two", 3:"three"}
print (d5.get(1) )#one
print (d5.get(5)) #None
print (d5.get(5, "test") )#test

d6 = {1:"one", 2:"two", 3:"three"}
print( d6.has_key(1) ) #True
print (d6.has_key(5))  #False

d7 = {1:"one", 2:"two", 3:"three"}
for item in d7.items():
    print (item)
#(1, 'one')
#(2, 'two')
#(3, 'three')
for key, value in d7.items():
    print ("%s -- %s" % (key, value))
#1 -- one
#2 -- two
#3 -- three

d8 = {1:"one", 2:"two", 3:"three"}
for key in d8.keys():
    print (key)
#1
#2
#3

d8 = {1:"one", 2:"two", 3:"three"}
for value in d8.values():
    print( value)
#one
#two
#three

d9 = {1:"one", 2:"two", 3:"three"}
print (d9.pop(1) )#one
print( d9) #{2: 'two', 3: 'three'}
print( d9.pop(5, None)) #None
try:
    d9.pop(5)  # raise KeyError
except KeyError, ke:
    print ( "KeyError:", ke) #KeyError:5

d10 = {1:"one", 2:"two", 3:"three"}
print (d10.popitem() ) #(1, 'one')
print (d10)  #{2: 'two', 3: 'three'}

d = {1:"one", 2:"two", 3:"three"}
print (d.setdefault(1))  #one
print (d.setdefault(5))  #None
print( d)  #{1: 'one', 2: 'two', 3: 'three', 5: None}
print (d.setdefault(6, "six")) #six
print (d)  #{1: 'one', 2: 'two', 3: 'three', 5: None, 6: 'six'}

d = {1:"one", 2:"two", 3:"three"}
d2 = {1:"first", 4:"forth"}
d.update(d2)
print (d)  #{1: 'first', 2: 'two', 3: 'three', 4: 'forth'}

d = {1:"one", 2:"two", 3:"three"}
for key, value in d.viewitems():
    print ("%s - %s" % (key, value))
#1 - one
#2 - two
#3 - three

d = {1:"one", 2:"two", 3:"three"}
for key in d.viewkeys():
    print( key)
#1
#2
#3

d = {1:"one", 2:"two", 3:"three"}
for value in d.viewvalues():
    print (value)
#one
#two
#three

numbers = ["zero", "one", "two", "three", "four"]
  
print (numbers[1] )# one
print (numbers[-1] )# four
#print( numbers[5]) # raise IndexError
print (numbers[:]) # ['zero', 'one', 'two', 'three', 'four']
print (numbers[3:]) # ['three', 'four']
print (numbers[:2]) # ['zero', 'one']
print (numbers[2:4] )# ['two', 'three']
print (numbers[1:-1] )# ['one', 'two', 'three']