Python 探坑

@ Hanks

简单、易学、免费、开源。
高层语言
可移植性
扩展性
丰富的库

运行慢

Hello world

# Python 2
print 'Hello World!'



# Python 3
print('Hello World!')

PEP 8

-- Style Guide for Python Code

语法

print "hello world"


# data type
a = 1
b = 1.0
c = "xitu.io"
d = False and True

# muilt-lines 
s = """ The big brown fox
quickly jump ed over the wall
and ran away.
"""
print r"Use \n fox new line" # raw string
print s
print 40 + 42.67
print int(67.879)
print float(12)
print long(345353524253453453453)
print "" + str(2)

# list  tuple dict

e = [a,b,c,d]
f = (a,b,c,d,e)
xiaoming = {'name':'XiaoMing', 'age':10, 'weight':12.3, 'like':['sport','music'] }

print e # [1, 1.0, 'xitu.io', False]
print f # (1, 1.0, 'xitu.io', False, [1, 1.0, 'xitu.io', False])
print xiaoming # {'age': 10, 'name': 'XiaoMing', 'weight': 12.3, 'like': ['sport', 'music']}


e[0] = 99
print e[0] # 99

print 1 in e # True

xiaoming['like'].append('sleep')


f[4][0] = 199
print f # (1, 1.0, 'xitu.io', False, [199, 1.0, 'xitu.io', False])




# if for while
age = 3
if age >= 18:
    print('adult')
elif age >= 6:
    print('teenager')
else:
    print('kid')
    

names = ['Michael', 'Bob', 'Tracy']
for name in names:
    print name
    
# 0 ~ 20
nums = [ i*2  for i  in range(21)   ]
print nums

a,b = b,a # swap

for key,value in xiaoming.items():
    print key
    print value



# function

def my_abs(x):
    if x >= 0:
        return x
    else:
        return -x
        
def power(x, n=2):
    s = 1
    while n > 0:
        n = n - 1
        s = s * x
    return s
    
    
def calc(*numbers): # numbers is tuple
    sum = 0
    for n in numbers:
        sum += n
    print sum
    return sum
    
calc(1, 3, 5, 7)
 
 
 
def person(name, age, **kw): # kw is dict
    print 'name:', name, 'age:', age, 'other:', kw

person('Michael', 30)
person('Bob', 35, city='Beijing')




# class

class Student(object):

    def __init__(self, name, score):
        self.name = name
        self.score = score
        
    def print_score(self):
        print '%s: %s' % (self.name, self.score)
        
    # def __str__(self):
    #     return 'Student object (name: %s)' % self.name
    
    # def __len__(self):
    #     return 100

bart = Student('Bart Simpson', 59)
bart.print_score()

print bart
# print len(bart)


# 1
a=[2,3,4,5]
b=[2,5,8]
tmp = [val for val in a if val in b]
print tmp


# 2
print list(set(a).intersection(set(b)))