First, the curriculum objectives
Learn the basics of reading and writing files
The use of third-party packages to read and write Word , Excel file
Second, the details of interpretation
01. basic operations:
# Interactive mode:
>>> f = open ( 'raise.txt' , 'w') # open the current working directory raise.txt file, if the file does not exist, create
>>> f.write('You raise me up.')
16 # write the contents of the file size
>>> f.close () # perform this step to be considered saved to a file
>>> import os
>>> os.getcwd () # to view the current working directory
'F:\\06python\\00pythonfullstackengineer\\chapter03'
>>> os.listdir () # file and view the files in the current working directory folder
['raise.txt']
>>> f = open ( 'raise.txt' ) # open the file in read-only mode
>>> f.read () # read the file contents
'You raise me up.'
>>> dir (f)
['_CHUNK_SIZE', '__class__', '__del__', '__delattr__', '__dict__', '__dir__', '_
_doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattrib
ute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '
__iter__', '__le__', '__lt__', '__ne__', '__new__', '__next__', '__reduce__', '_
_reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclassho
ok__', '_checkClosed', '_checkReadable', '_checkSeekable', '_checkWritable', '_f
inalizing', 'buffer', 'close', 'closed', 'detach', 'encoding', 'errors', 'fileno
', 'flush', 'isatty', 'line_buffering', 'mode', 'name', 'newlines', 'read', 'rea
dable', 'readline', 'readlines', 'reconfigure', 'seek', 'seekable', 'tell', 'tru
ncate', 'writable', 'write', 'write_through', 'writelines']
# Write to the file content with context manager way, you can not perform the close () operation.
>>> with open('raise.txt', 'a') as f:
... f.write(' so I can stand on mountains. \nYou raise me up to walk on stor
my sea. \nI am strong when I am on your shoulders.')
...
111
# View content just written
>>> f = open('raise.txt')
>>> for line in f: # here f is iterables
... print(line, end='')
...
You raise me up. so I can stand on mountains.
You raise me up to walk on stormy sea.
I am strong when I am on your shoulders.>>>
>>>
>>> f.read()
' # At this time the file pointer points to the end of file has, and then read on an empty string
# To operate the file pointer location, can seek () function
>>> help(f.seek)
Help on built-in function seek:
seek(cookie, whence=0, /) method of _io.TextIOWrapper instance
Change stream position.
Change the stream position to the given byte offset. The offset is
interpreted relative to the position indicated by whence. Values
for whence are:
* 0 -- start of stream (the default); offset should be zero or positive
* 1 -- current stream position; offset may be negative
* 2 -- end of stream; offset is usually negative
Return the new absolute position.
>>> f.seek(0) # 将文件指针移动到开始位置
0
>>> f.read(3) # 从文件开始位置向后读取 3个 字符
'You'
>>> f.readline() # 从指针所在位置读到行末
' raise me up. so I can stand on mountains. \n'
>>> f.readlines() # 从指针所在位置逐行读取内容，返回列表，一行作为列表的一个元素
['You raise me up to walk on stormy sea. \n', 'I am strong when I am on your sho
ulders.']
02.特定类型文件：
1).word： pip install python-docx
# 交互模式下：
>>> from docx import Document
>>> d = Document() # 实例化一个Document对象
>>> d.add_paragraph('Life is short, You need Python.') # 添加段落
<docx.text.paragraph.Paragraph object at 0x0280D2F0>
>>> d.save('python.docx') # 保存，执行到这一步才算保存到文件中
>>> import os
>>> os.listdir()
['python.docx', 'raise.txt']
>>> f = open('python.docx', 'rb') # 以只读二进制模式打开文件
>>> doc = Document(f)
>>> doc
<docx.document.Document object at 0x02803E40>
>>> doc.paragraphs
[<docx.text.paragraph.Paragraph object at 0x0280D710>]
>>> for i in doc.paragraphs: # 逐行循环打印出python.docx文件的内容
function(){ //MT4买卖价 http://www.fx61.com/faq/muniu/436.html
... print(i.text)
...
Life is short, You need Python.
# 在world添加图片
>>> d.add_picture('laoqi.jpg')
<docx.shape.InlineShape object at 0x00851F70>
>>> d.save('python.docx') # 注意图片是按原始大小放入word文档的
.excel： pip install openpyxl
用上式安装失败的同学可以用这个：pip install -i https://pypi.tuna.tsinghua.edu.cn/simple openpyxl
# 交互模式下：
>>> from openpyxl import Workbook
>>> wb = Workbook()
>>> ws = wb.active # 获取工作薄里的工作表
>>> ws.title # 获取工作表的名称
'Sheet'
>>> ws.title = 'python' # 修改工作表的名称
>>> ws1 = wb.create_sheet('rust') # 创建一个新的工作表
>>> ws1.title # ws1工作表的名称
'rust'
>>> wb.sheetnames # 工作表的所有表的表名
['python', 'rust']
# 往工作表中写入数据
>>> ws['E1'] = 123 # 第E列第1行写入 123
>>> ws.cell(row=2, column=3, value=111) # 第2行第3列写入 111
<Cell 'python'.B2>
>>> wb.save('excel.xlsx') # 将数据保存到 excel.xlsx 中