Python basic file operations and cursor movement details

Mode 1:
	f = open(file path, read-write mode, encoding='utf8')
	()
Mode 2:  # The close method is automatically called to close the resource after the subcode has finished running
	with open(file path, read-write mode,encoding='utf8') as f: 
prerequisites:
# 1, the first parameter of the open method is the path of the file, and crowbar with a combination of some letters will produce a special meaning of the path to find a confusing In order to solve the problem you can add the letter r in front of the path in the string
	D:\a\n\t
	r'D:\a\n\t'
# 2. with can open multiple files at once.
	with open() as f1,open() as f2,open() as f3:

	read-only (computing)，unwritten
1.File path does not exist：Direct error.
	with open(r'','r',encoding='utf8') as f:
		print(())
2.File path exists：Normal readout
	with open(r'', 'r', encoding='utf8') as f:
		print(())

	can only write，unwatchable
1.File path does not exist：  # Create new documents
	with open(r'','r',encoding='utf8') as f:
		pass
2.File path exists：  # Empty the contents of the file before rewriting it
	with open(r'', 'r', encoding='utf8') as f:
		('Writing content')
prerequisites：
# 1, the contents of the preparation need to add their own line breaks, after saving u while to pay attention to the existence of his

	Data can only be added at the end of the file
1.File path does not exist：  # Create new documents
	with open(r'','a',encoding='utf8') as f:
		pass
2.File path exists：  # Add at the end of the document
	with open(r'', 'a', encoding='utf8') as f:
		('Writing content')

	Text mode is the default mode
1、Read/Write Mode Abbreviation：r、w、a
       	full name：rt、wt、at
prerequisites：
# 1. Only text files can be operated
# 2, read and write in characters
# 3, you need to specify the encoding parameter, do not fill in the default encoding of the computer is used

	byteparadigm
1、不是默认的paradigm，It needs to be specified to generate
		rb、wb、ab
prerequisites：
# 1, can operate any file
# 2. Reads and writes are in bytes.
# 3. No need to specify the encoding parameter, no need for encoding

code performance：
	filename.read()
prerequisites：
# 1, read the contents of the file at once, and the cursor stays at the end of the file, continue to read no content
# 2, when the content of the file is relatively large, the method may also cause the computer memory overflow
# 3, the brackets can be filled with numbers, in the text mode, that reads a few characters
# 4. Usually three bytes (or more) for a Chinese character and one byte for an English letter.

code performance:
    for data value in Documents to be traversed：
prerequisites：
# 1, line by line to read the contents of the file to avoid memory overflows

1、readline
	code performance：
    filename.readline()
	prerequisites：
	# 1. Read one line at a time
2、readlines
	code performance：
    filename.readline()
   prerequisites：
	# 1, read the contents of the file at once, will be organized in accordance with the number of lines into a list of individual data values

code performance：
	code performance：
    filename.readable()
prerequisites：
# 1, to determine whether the file has the ability to read data

1、write
	Used to write specified data to a file
	code representation：
    f = open("", 'w')
    ("Write a new line of data.")
    ()
2、writeable
	Used to determine if a file is writable
	code representation：
    f = open("", "a")
    print(())
    	can be written to： Ture
    	unwritable： False
3、writelines
	Used to receive a list，Write all the data in the list at once
	code representation：
    f = open('', 'r')
    n = open('','w+')
    (())
    ()
    ()

	 file_object.flush()

	Move the read pointer of a file to a specified location。seekFunctions need to be called using a file object，No return value。
	seek()There are three uses：
   	seek(offset,whence)
    offset  Controls the amount of displacement for cursor movement(nibbles)
    whence  paradigm
        0   基于文件开头移动多少nibbles
        1   基于光标当前所在位置移动多少nibbles
        2   基于文件末尾移动多少nibbles
    ps:1respond in singing2只能在二进制paradigm下使用 0cannot be said be

	Used to get the current position of the cursor（Number of bytes moved）
    code representation：
    filename.tell()
    # Returns the number of bytes the cursor is currently in