python统计文件行数

 '''
import time
time_start=time.time()
count=0  
fp=open("base.log","r")  
while 1:  
    buffer=fp.read(8*1024*1024)  
    if not buffer:  
        break  
    count+=buffer.count('\n')  
    #print("count:"+str(count))  
print("all count:"+str(count))
time_end=time.time()
print("use time:", time_end - time_start)
print("over")  
fp.close()
'''
import time
time_start2=time.time()
fr=open("base.log", "r")
line = fr.readline()
count2 = 0
while line:
    #print(line)
    
    line = fr.readline()
    
    count2 = count2 + 1
    #print(str(count))
fr.close()
print("all count2:"+str(count2))
time_end2=time.time()
print("use time:", time_end2 - time_start2)
print("over") 

分为两种法法，前面一种是网上找的比较高大上的方法，发现只有在文件小的时候会效率好

后面一种方法是最朴实的一行一行算，效率还可以。统计的是一个1.5G大小的文件，千万级别，结果如下所示：

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>>> 
========= RESTART: E:/02-公司事务资料/2-ORBI/log analysis/count_number.py =========
all count:12303830
use time: 21.817627429962158
over
all count2:12303831
use time: 12.469038963317871
over
>>> 
========= RESTART: E:/02-公司事务资料/2-ORBI/log analysis/count_number.py =========
all count:12303830
use time: 21.56630301475525
over
>>> 
========= RESTART: E:/02-公司事务资料/2-ORBI/log analysis/count_number.py =========
all count2:12303831
use time: 13.03462815284729
over
>>>