Python之基础（二）

1、内建函数enumerate

friends = ['john', 'pat', 'gary', 'michael']
for i, name in enumerate(friends):
    print "iteration {iteration} is {name}".format(iteration=i, name=name)

　　其中 i 表示：0， 1， 2， 3；

　　name表示：friends下标为i的内容，即friends[i]

2、print()格式化输出

parents, babies = (1, 1)
while babies < 100:
    print("This generation has %s babies" % (babies))
    parents, babies = (babies, parents + babies)

3、函数定义并调用

def greet(name):
    print("Hello, my name is %s." % name)
    #print("Hello, my name is %s." % (name))
greet('huabo')
greet('yanyan')

4、import模块，字符串匹配

import re
for test_string in ['555-1212', 'ILL-EGAL']:
    if re.match(r'^\d{3}-\d{4}$', test_string):
        print("%s is a valid UI local phone number" % test_string)
    else:
        print("%s rejected" % test_string)

　　输出：

555-1212 is a valid UI local phone number
ILL-EGAL rejected

5、Dictionaries, generator expressions

prices = {'apple': 0.40, 'banana': 0.50}
my_purchase = {
    'apple': 1, 'banana': 6}
grocery_bill = sum(prices[fruit] * my_purchase[fruit]
                   for fruit in my_purchase)
print('I owe the grocer $%.2f' % grocery_bill)

　　0.4*1+0.5*6 = 3.4

6、 Opening files and output all the content.

#indent your python code to put into an email
import glob

#out put all the Python files in the current Directory.
python_files = glob.glob('*.py')
for file_name in sorted(python_files):
    print("    ------%s" % file_name)

    with open(file_name) as f:
        for line in f:
            print(line.rstrip())

    print()

7、时间，条件，输出

from time import localtime
activities = {8: 'Sleeping',
              9: 'Commuting',
              17: 'Working',
              18: 'Commuting',
              20: 'Eating',
              22: 'Resting' }

time_now = localtime()
print('Current Time: %sYear %sMonth %sDay %sHour %sMin' % (time_now.tm_year, time_now.tm_mon, time_now.tm_mday, time_now.tm_hour, time_now.tm_min))

hour = time_now.tm_hour

for activity_time in sorted(activities.keys()):
    if hour < activity_time:
        print(activities[activity_time])
        break
else:
    print('Unknown, AFK or sleeping!')

8、三单引号字符串

REFRAIN = '''
%d bottles of beer on the wall,
%d bottles of beer,
take one down, pass it around,
%d bottles of beer on the wall!
'''

bottles_of_beer = 8
while bottles_of_beer > 1:
    print(REFRAIN % (bottles_of_beer, bottles_of_beer, bottles_of_beer - 1))
    bottles_of_beer -= 1
    

　　注意：三单引号字符串可以使得字符串可以换行，很方便。