格式化输出
- reprlib
1 2 3
import reprlib reprlib.repr(set('supercalifragilisticexpialidocious')) #"{'a', 'c', 'd', 'e', 'f', 'g', ...}" - pprint
1
2
3
4
5
6
7
8
9
import pprint
t = [[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta',
'yellow'], 'blue']]]
pprint.pprint(t, width=30)
#[[[['black', 'cyan'],
# 'white',
# ['green', 'red']],
# [['magenta', 'yellow'],
# 'blue']]]
- textwrap
1
2
3
4
5
6
7
8
9
import textwrap
doc = """The wrap() method is just like fill() except that it returns
a list of strings instead of one big string with newlines to separate
the wrapped lines."""
print(textwrap.fill(doc, width=40))
#The wrap() method is just like fill()
#except that it returns a list of strings
#instead of one big string with newlines
#to separate the wrapped lines.
- locale
1
2
3
4
5
6
7
8
9
10
import locale
locale.setlocale(locale.LC_ALL, 'English_United States.1252')
'English_United States.1252'
conv = locale.localeconv() # get a mapping of conventions
x = 1234567.8
locale.format("%d", x, grouping=True)
#'1,234,567'
locale.format_string("%s%.*f", (conv['currency_symbol'],
conv['frac_digits'], x), grouping=True)
#'$1,234,567.80'
多线程
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
import threading, zipfile
import time
class TestThread(threading.Thread):
def __init__(self, instring):
threading.Thread.__init__(self)
self.out=instring
def run(self):
time.sleep(10)
print(self.out)
background = TestThread('test string...')
background.start()
print('The main program continues to run in foreground.')
background.join() # Wait for the background task to finish
print('Main program waited until background was done.')
日志输出
1
2
3
4
5
6
import logging
logging.debug('Debugging information')
logging.info('Informational message')
logging.warning('Warning:config file %s not found', 'server.conf')
logging.error('Error occurred')
logging.critical('Critical error -- shutting down')
列表操作
- bisect
1 2 3 4 5
import bisect scores = ['a','aa','aaa','aaaaa','aaaaaaaaaa'] bisect.insort(scores, 'aaaa') print(scores) #['a', 'aa', 'aaa', 'aaaa', 'aaaaa', 'aaaaaaaaaa']
- deque
1 2 3 4 5
from collections import deque d = deque(["task1", "task2", "task3"]) d.append("task4") print("Handling", d.popleft(),d.pop()) #Handling task1 task4 - array
1 2 3 4 5 6
from array import array a = array('H', [4000, 10, 700, 22222]) print(sum(a)) print(a[1:3]) #26932 array('H', [10, 700]) - heapq
1 2 3 4 5 6
from heapq import heapify, heappop, heappush data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0] heapify(data) # rearrange the list into heap order heappush(data, -5) # add a new entry [heappop(data) for i in range(3)] # fetch the three smallest entries #[-5, 0, 1]
浮点数
- decimal
1 2 3 4 5
from decimal import * round(Decimal('0.70') * Decimal('1.05'), 2) #Decimal('0.74') round(.70 * 1.05, 2) #0.73