Study Group: 巾凡哥出品 品質保證 python 07

File Processing & Module

f = open(file="file.txt")
print(f.read())

• cursor

f = open(file="file.txt")
print(f.read()) # print the content
print(f.read()) # print empth content

• close file

f = open(file="file.txt")
f.close()
f.read()

• with

with open("file.txt") as t:
    content = t.read()
print(content)

• wiht text to a file

with open('file.txt', 'w') as file:
    file.write('test')

Append a file

Character	Meaning
‘r’	open for reading (default)
‘w’	open for writing, truncating the file first
‘x’	create a new file and open it for writing
‘a’	open for writing, appending to the end of the file if it exists
‘b’	binary mode
‘t’	text mode (default)
’+’	open a disk file for updating (reading and writing)
‘U’	universal newline mode (deprecated)

• Append a file
  • x: Only works when the file doesn’t exist
  • a: Append contents to the end of the file, and move the cursor to the end
  • +: Support read and write the same file at the same time

       with open('fruits.txt', 'a') as file:
           file.write('\nBanana\n')
  

• Read and Write

with open(‘fruits.txt’, ‘a+’) as file:
   file.write('Banana\n') # <= Cursor moves to the end of file
   file.seek(0) # <= Cursor moves to position 0
   content = file.read() # <= Cursor moves to the end of file
   file.write(content)

• exercise 寫三次

with open('file.txt', 'a+') as r:
  r.seek(0)
  content = r.read()
  print(content)
  r.write('\n')
  r.write(content)
  r.write('\n')
  r.write(content)