Working with files in Python
Working with files in Python
Open and read file
Files can be open for reading, writing and appending in binary and text mode. Pythong give a lot of different ways to work with files.# r – read (default, can be omitted), w-write, a-append, r+ - read write
Read whole file in one go
It is possible to read all file in one go
f = open("test.txt","r", encoding="utf-8") # open file for reading in text mode utf-8 codding
x = f.read() # read all file into x
f.close() # close file
print(x) # print content of this file
print(repr(x)) # print contend of this file with showing all special symbols
y=x.splitlines() # y – list of lines without ‘end of line’ symbols
If you will give parameters for read(N) – it will read next N-characters. You need to be careful with this parameters. It will read N-characters in selected coding. By default it will read N-bytes. If the file encoding will be stated, it will read N- characters in this encoding.
Read file by lines
If file is pretty big, it is better to read it line by line and process accordingly
f = open("test.txt","r", encoding="utf-8") # open file for reading
for line in f:
line = line.rstrip() # remove enf of line
print(line) # use our line from file
f.close()
Open and immediately close file
To avoid any problems with file, it is better to close it immediately after use. Python give very simple tool for closing file immediately after reading
with open("test.txt","r", encoding="utf-8") as f:
for line in f:
line = line.rstrip()
print( line )
# at the end of block WITH, file will be closed automatically
Work with few files together
Python allow to work in WITH block with few files together
with open("test.txt","r", encoding="utf-8") as f, open("test_copy.txt", "w") as w:
for line in f:
w.write(line)
# at the end of block WITH, file “test.txt” will be copied to “test_copy.txt”
Published: 2021-09-29 07:15:43
Updated: 2021-09-29 08:19:44