##Python3 学习笔记

#Dictionary
'''
dict{}
dict={'keyword': value}
'''
#!/usr/bin/python3
tel = {'jack': 4098, 'sape': 4139}
tel['guido'] = 4127
print(tel)
print(tel['jack'])
del tel['sape']
print(tel)
tel['irv'] = 4127
print(tel)
print(list(tel.keys()))
t = sorted(tel.keys())
print(t)
x = dict([('sape',4139),('guido',4127),('jack',4098)])
print(x)
y = dict(sape=4139,guido=4127,jack=4098)
print(y)

#遍历技巧
knights = {'gallahad': 'the pure', 'robin':'the brave'}
print(knights.items())
for k,v in knights.items():
    print(k,v)

#不是很懂,为什么输出是robin the brave, gallahad the pure,因为knights的items里面没有k这个字母啊
#k,v代表的是key, value!!!!!!

for i,v in enumerate(['tic','tac','toe']):
    print(i,v)

#遍历两个或更多的序列,可以用zip()组合
#最后的what is your {0}, it is {1}, 必须加".format(q,a))这样{0}{1}才有对应的数值输出。
questions = ['name','quest','favorite color']
answers = ['lancelot','the holy grail','blue']
for q,a in zip(questions,answers):
    print('What is your {0}? It is {1}.'.format(q,a))
##等同于用%s
    print('what is your %s? it is %s' %(q,a))


##反向遍历一个序列,用reversed()函数
for i in reversed(range(1,10,2)):
    print(i)

#列表中其实也是可以可以用的 list.reverse()
## 你还记得如果是bash的倒叙应该是怎么写吗?
## 找回来。。。死记硬背背下来啊。

#按顺序来遍历书序,使用sorted()
basket = ['apple','orange','apple','pear','orange','banana']
for f in sorted(set(basket)):
    print(f)

'''
[x*y for x in range[1,5] if x > 2 for y in range[1,4] if x < 3]
他的执行顺序是
for x in range[1,5]
    if x > 2
        for y in range[1,4]
            if x < 3
                x*y
'''
#####################################################3

#Python3模块
#!/usr/bin/python3
#filename: using_sys.py

import sys

print('命令行参数如下:')
for i in sys.argv:
    print(i)
print('\n\nPython 路径为:',sys.path,'\n')

##import语句
#这个就是先自己自定义函数,保存为support.py,然后再新建一个test.py来引入support模块
#!/usr/bin/python3
#Filename:support.py

def print_func(par):
    print("Hello:",par)
    return

#!/usr/bin/python3
#Filename:test.py

import support
support.print_func("Runoob")

##最后结果为Hello:Runoob

##############

import sys
print("The path for python is:", sys.path)

#The path for python is: ['F:\\python-learn', 'F:\\python-learn', 'F:\\python35.zip', 'F:\\DLLs', 'F:\\lib']

#############
 
 

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转载自blog.csdn.net/cyx441984694/article/details/78448703