python字符串过滤性能比较5种方法比较
总共比较5种方法。直接看代码：
import randomimport timeimport osimport stringbase = string.digits+string.punctuationtotal = 100000def loop(ss): """循环""" rt = '' for c in ss: if c in '0123456789': rt = rt + c return rtdef regular(ss): """正则表达式""" import re rt = re.sub(r'D', '', ss) return rtdef filter_mt(ss): """函数式""" return filter(lambda c:c.isdigit(), ss)def list_com(ss): """列表生成式""" isdigit = {'0': 1, '1': 1, '2': 1, '3': 1, '4': 1, '5':1, '6':1, '7':1, '8':1, '9':1}.has_key return ''.join([x for x in ss if isdigit(x)])def str_tran(ss): """string.translate()""" table = string.maketrans('', '') ss = ss.translate(table,string.punctuation) return ssif __name__ == '__main__': lst = [] for i in xrange(total): num = random.randrange(10, 50) ss = '' for j in xrange(num): ss = ss + random.choice(base) lst.append(ss) s1 = time.time() map(loop,lst) print "loop: ",time.time() - s1 print '*'*20 s1 = time.time() map(regular, lst) print "regular: ", time.time() - s1 print '*' * 20 s1 = time.time() map(str_tran, lst) print "str_tran: ", time.time() - s1 print '*' * 20 s1 = time.time() map(filter_mt, lst) print "filter_mt: ", time.time() - s1 print '*' * 20 s1 = time.time() map(list_com, lst) print "list_com: ", time.time() - s1
