[记]python不同方式行数获取速度对比

Code:1

t1 = time.time()

fiew = open(r".\3.txt","r")
count =len(["" for line in fiew])

t2 = time.time()-t1
print(count)
print(t2)

打印输出

3333333
0.43785786628723145

Code:2

t1 = time.time()

fiew = open(r".\3.txt","r")
count=0
for line in fiew:
    count+=1

t2 = time.time()-t1
print(count)
print(t2)

打印输出

3333333
0.5445420742034912

Code:3

t1 = time.time()

fiew = open(r".\3.txt","r")
count=len(fiew.readlines())

t2 = time.time()-t1
print(count)
print(t2)

打印输出

3333333
0.4448392391204834 

 附：超大文本文件获取指定行的方法

fiew = open(r".\3.txt","r")
countt=0
for line in fiew:
    if countt in [2333,2334,2335,2336,2337,2338,2339]: 
        print(line)
        print("---")
    countt+=1

2333

--- 
2334
    
--- 
2335
    
--- 
2336

---
2337

---
2338

---
2339

---