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In this article, Xiaobian introduces in detail how to create, append, and overwrite csv files for you, with detailed contents, clear steps and proper handling of details. I hope this article "how to create python, append and overwrite csv files" can help you solve your doubts.

Python read and write csv file creation

Using the writer function in the csv package, if the file does not exist, it will be created automatically. It should be noted that the file suffix must be .csv, so that the csv file will be created.

Here, the file is created and the header information of the csv file is written into the file.

Import csvdef create_csv (): path = "aa.csv" with open (path,'wb') as f: csv_write = csv.writer (f) csv_head = ["good", "bad"] csv_write.writerow (csv_head) append

In python, opening it in a + mode is appended

Def write_csv (): path = "aa.csv" with open (path,'a+') as f: csv_write = csv.writer (f) data_row = ["1", "2"] csv_write.writerow (data_row) read

Using csv.reader, we can read the csv file, and then return an iterative object csv_read. We can fetch data directly from csv_read.

Def read_csv (): path = "aa.csv" with open (path, "rb") as f: csv_read = csv.reader (f) for line in csv_read: print line additional

The way python uses open to open files:

W: open in write mode

A: open in append mode (starting with EOF and creating new files if necessary)

Ringing: open in read-write mode

Read: open in read-write mode (see w)

Asides: open in read-write mode (see a)

Rb: open in binary read mode

Wb: open in binary write mode (see w)

Ab: open in binary append mode (see a)

Rb+: opens in binary read-write mode (see r +)

Wb+: opens in binary read-write mode (see w +)

Ab+: opens in binary read-write mode (see a +)

Batch generation of csv files

The name of the generated txt file is not known in advance, and its name generates txt files with different names according to different data ranges, which is mainly realized by str (x) + '.txt'.

Here's a simple example.

Write the data to the n1-n2.txt, N1, and N2 is generated by the loop.

Import pandas as pda = [1jue 2], [3je 4]] data = DataFrame (path= indexC:\ Users\ Administrator\ Desktop\ files'for i in range (0jue 4): X = data.to_csv (os.path.join (path,str (I) +'-'+ str (j) + '.txt'), sep='.

Running result:

Apply str (I) +... + '.txt' can generate a file with any name.

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