In [129]:
## 比較函示
'''
Equal to (==)
Not equal to (!=)
Less than (<)
Less than or equal to (<=)
Greater than (>)
Greater than or equal to (>=)
'''
##比較函示會吐出True or False
a = 5 > 4
print a
b = 5 == 4
print b
In [130]:
## and 兩者皆真為真
## or 兩者有一真為真
## not 否定
#真值表
a = True and True
b = True and False
c = False and False
d = True or True
e = True or False
f = False or False
g = not False
print a, b, c, d, e, f, g
In [131]:
# if, elif and else
a = -1
if a > 3:
print "a > 3"
elif a == 3:
print "a = 3"
else:
print "a < 3"
In [132]:
#Python 是物件導向語言
#每個東西都是物件，不同的物件之中有不同的方法來操作
class car:
wheel = 4
max_speed = 90
#建立物件時自動呼叫的方法，參數預設要加入"self"
def __init__(self):
print "Let's Go!"
def get_wheel(self):
print "wheel = ", self.wheel
def set_max_speed(self,speed):
if speed > self.max_speed:
print "Too Fast!"
elif (speed <= self.max_speed) & (speed > 0):
print "Safe!"
else:
print "Stop"
#我們不能直接操作物件，要操作物件之前，必須將物件實體化
car = car()
car.get_wheel()
car.set_max_speed(0)
In [133]:
##建立方法
def test():
print "It's my first function in Python!"
test()
In [134]:
## 加入參數
def tax(income):
tax = 1.035
return income * tax
tax(50000)
# str(tax(50000))
#有關浮點數運算的誤差可以參考這篇:
#http://www.codedata.com.tw/python/python-tutorial-the-2nd-class-1-numeric-types-and-string/
Out[134]:
In [135]:
#PYTHON在設定參數的時候，不用指定參數型態
def super_print(x):
print x
super_print("cool")
super_print(13+5)
super_print([1,2,3,4,5])
In [136]:
def super_print(x):
for i in x:
print i
super_print("cool")
#super_print(13+5)
super_print([1,2,3,4,5])
In [137]:
#list 就是 array
zoo_animals = ["pangolin", "cassowary", "sloth", "cool"];
if len(zoo_animals) > 3:
print "The first animal at the zoo is the " + zoo_animals[0]
print "The second animal at the zoo is the " + zoo_animals[1]
print "The third animal at the zoo is the " + zoo_animals[2]
print "The fourth animal at the zoo is the " + zoo_animals[3]
In [138]:
numbers = [1,2,3,4]
print "數列長度: ",len(numbers)
print numbers[0]
print numbers[1]
print numbers[2]
print numbers[3] + numbers[1]
In [139]:
## change the content of a list
numbers[3] = 5
print numbers
numbers.append(10)
print "append : ", numbers
numbers.insert(2,100)
print "insert : ",numbers
##只能移除第一個碰到的元素
numbers.remove(100)
print "remove : ",numbers
numbers.sort()
print "sort : ",numbers
In [140]:
## cut the lis
numbers_a = numbers[1:4]
print numbers_a
numbers_b = numbers[:4]
print numbers_b
numbers_c = numbers[1::2]
print numbers_c
In [141]:
## 三倍長度
print 3 * numbers
## 分別操作list中的每個元素
for i in numbers:
print i
for i in numbers:
print i * 3
In [142]:
# Dictionary 就是key and value
residents = {'Puffin' : 104, 'Sloth' : 105, 'Burmese Python' : 106}
print residents['Puffin'] # Prints Puffin's room number
print residents["Sloth"]
print residents["Burmese Python"]
In [143]:
#建立新的key
residents['Bryan']=107
print "create a new key: ", residents
#改變value
residents['Bryan']=207
print "change a key: ",residents['Bryan']
#移除key
del residents["Bryan"]
print "remove a key: ",residents
In [144]:
# 用for迴圈操作list
for i in residents:
print i, residents[i]
In [145]:
def room(name):
for n in residents:
if n == name:
print name, "is living in room",residents[n]
##若已經找到對象，則跳脫迴圈
break
##如果for迴圈結束後沒有結果，則跳到else
else:
print "There is no this man"
room("Puffin")
In [146]:
#Dictionary 內部的value可以放的東西
inventory = {
'gold' : 500,
'pouch' : ['flint', 'twine', 'gemstone'], # Assigned a new list to 'pouch' key
'backpack' : ['xylophone','dagger', 'bedroll','bread loaf']
}
# Adding a key 'burlap bag' and assigning a list to it
inventory['burlap bag'] = ['apple', 'small ruby', 'three-toed sloth']
# Sorting the list found under the key 'pouch'
inventory['pouch'].sort()
# Your code here
inventory["pocket"] = ["seashell","strange berry", "lint"]
inventory["backpack"].sort()
inventory["backpack"].remove("dagger")
inventory["gold"]+=50
print inventory