Python2 基础语法(四)

import sys
s = sys.stdin.readline()
sys.stdout.write(s)

print

str()

x[key]

len()

class Array:
__list = []

def __init__(self):
print "constructor"

def __del__(self):
print "destructor"

def __str__(self):
return "this self-defined array class"

def __getitem__(self, key):
return self.__list[key]

def __len__(self):
return len(self.__list)

def Add(self, value):
self.__list.append(value)

def Remove(self, index):
del self.__list[index]

def DisplayItems(self):
print "show all items----"
for item in self.__list:
print item

arr = Array()   #constructor
print arr    #this self-defined array class
print len(arr)   #0
arr.Add(1)
arr.Add(2)
arr.Add(3)
print len(arr)   #3
print arr[0]   #1
arr.DisplayItems()
#show all items----
#1
#2
#3
arr.Remove(1)
arr.DisplayItems()
#show all items----
#1
#3
#destructor

def powersum(power, *args):
total = 0
for i in args:
total += pow(i, power)
return total

print powersum(2, 1, 2, 3)   #14

def displaydic(**args):
for key,value in args.items():
print "key:%s;value:%s" % (key, value)

displaydic(a="one", b="two", c="three")
#key:a;value:one
#key:c;value:three
#key:b;value:two

func = lambda s: s * 3
print func("peter ")  #peter peter peter

func2 = lambda a, b: a * b
print func2(2, 3)  #6

cmd = "print 'hello world'"
exec cmd   #hello world

expression = "10 * 2 + 5"
print eval(expression)    #25

AssertionError

flag = True

assert flag == True

try:
assert flag == False
except AssertionError, err:
print "failed"
else:
print "pass"

arr = [1, 2, 3]
print `arr`    #[1, 2, 3]
print repr(arr)    #[1, 2, 3]

import cPickle
import os
import sys

class Contact:
def __init__(self, name, phone, mail):
self.name = name
self.phone = phone
self.mail = mail

def Update(self, name, phone, mail):
self.name = name
self.phone = phone
self.mail = mail

def display(self):
print "name:%s, phone:%s, mail:%s" % (self.name, self.phone, self.mail)

# begin

# file to store contact data
data = os.getcwd() + os.sep + "contacts.data"

while True:
print "-----------------------------------------------------------------------"
operation = raw_input("input your operation(add/delete/modify/search/all/exit):")

if operation == "exit":
sys.exit()

if os.path.exists(data):
if os.path.getsize(data) == 0:
contacts = {}
else:
f = file(data)
contacts = cPickle.load(f)
f.close()
else:
contacts = {}

if operation == "add":
flag = False
while True:
name = raw_input("input name(exit to back choose operation):")
if name == "exit":
flag = True
break
if name in contacts:
print "the name already exists, please input another or input 'exit' to back choose operation"
continue
else:
phone = raw_input("input phone:")
mail = raw_input("input mail:")
c = Contact(name, phone, mail)
contacts[name] = c
f = file(data, "w")
cPickle.dump(contacts, f)
f.close()
print "add successfully."
break
elif operation == "delete":
name = raw_input("input the name that you want to delete:")
if name in contacts:
del contacts[name]
f = file(data, "w")
cPickle.dump(contacts, f)
f.close()
print "delete successfully."
else:
print "there is no person named %s" % name
elif operation == "modify":
while True:
name = raw_input("input the name which to update or exit to back choose operation:")
if name == "exit":
break
if not name in contacts:
print "there is no person named %s" % name
continue
else:
phone = raw_input("input phone:")
mail = raw_input("input mail:")
contacts[name].Update(name, phone, mail)
f = file(data, "w")
cPickle.dump(contacts, f)
f.close()
print "modify successfully."
break
elif operation == "search":
name = raw_input("input the name which you want to search:")
if name in contacts:
contacts[name].display()
else:
print "there is no person named %s" % name
elif operation == "all":
for name, contact in contacts.items():
contact.display()
else:
print "unknown operation"