#!/usr/bin/env python
# Author:liujun
f = open("test","r",encoding="utf-8")
# r --> readable
# r --> writeable
# r+ --> read and write
# w+ --> write and read
#print(f.read())
#for i in range(5):
# print(f.readline())
#for line in f.readlines():
# print(line.strip())
#for index,line in enumerate(f.readlines()):
# print(index,line.strip())
#for line in f: # This kind of traverse is recommanded
# print(line.strip())
print(f.tell())
print(f.readline())
print(f.tell())
# Used to get the location of file pointer.
f.seek(10)
# Used to set the location of file pointer
print(f.read(50))
print(f.readline())
print(f.fileno())
f.flush()
# Forces the contents of the cache to be written to disk.
How to modify a file
#!/usr/bin/env python
# Author:liujun
f = open("test", "r", encoding="utf-8")
f_new = open("test.bak","w",encoding="utf-8")
for line in f:
if "iphone" in line:
line = line.replace("iphone","iphoneX");
f_new.write(line)
f.close()
f_new.close()