Two ways to open a file

f = open("data.txt","r")   #Setting the file object

f.close() #Close file

#For convenience, and to avoid forgetting to close the file object, you can use the following instead

with open('data.txt',"r") as f:    #Setting the file object

    str = f.read()

Some simple operations on documents

1.Read files

f = open("data.txt","r")   #Setting the file object

str = f.read()     #Read all the contents of the txt file into the string str

f.close()   #Close the file

2.Read the entire file by line

#The first method

f = open("data.txt","r")   #Setting the file object

line = f.readline()

line = line[:-1]

while line:             #Until the file is read

    line = f.readline()  #Read a line of file, including line breaks

    line = line[:-1]     #Remove line breaks, or not

f.close() #Close file

 

 

#The second method

data = []

for line in open("data.txt","r"): #Set the file object and read each line of the file

    data.append(line)               #Add each line of the file to the list

 

 

#The third method

f = open("data.txt","r")   #Setting the file object

data = f.readlines()  #Read the file directly into the list by line, with the same effect as method 2

f.close()             #Close file

3.Write file

Simply write a string to txt

with open('data.txt','w') as f:    #Setting the file object

    f.write(str)                 #Writing a string to a file

4.List write file

data = ['a','b','c']

#Single-level list write file

with open("data.txt","w") as f:

    f.writelines(data)

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