1. 使用print("string", file="")来实现
with open('./hello','wt') as f:
for i in range(4979):
print("chr{0}\t{1}\t{2}".format(1,i*50000,(i+1)*50000),file=f)
2. 使用sys来实现
import sys
savedStdout = sys.stdout #保存标准输出流
with open('./hello', 'wt') as file:
sys.stdout = file #标准输出重定向至文件
print('This message is for file!')
print("chr{0}\t{1}\t{2}".format(1,i*50000,(i+1)*50000))
sys.stdout = savedStdout #恢复标准输出流
print ('This message is for screen!')
输出大文件前几行（类似R head()）
import os
os.chdir("./test")
k=50
with open("85.txt") as f:
n=0
for line in f.readlines():
n+=1
print(line.replace("\n",""))
if n==k:
break
