write and writelines

Learn writing with write and writelines.

write and writelines

To write text into a file, use the write method: f.write("Hello\n"). This method writes the string as is; you add the \n for a line break yourself. The return value is the number of characters written.

To write many lines at once, use writelines: f.writelines(["a\n", "b\n", "c\n"]). It writes the list of strings in order; it doesn't add \n between them, so you add it yourself.

The write return value

The write method returns the number of characters written. If you write n = f.write("Hello world"), then n is 11. This is handy for tracking progress with large data.

Turkish characters can take more than one byte in UTF-8; still, write returns the character count. To see the byte count, you'd need to open the file in binary mode.

Exercise Write three lines with writelines

Open a file for writing: f = open("list.txt", "w", encoding="utf-8"). Write three lines with f.writelines(["apple\n", "pear\n", "cherry\n"]) and close it. Reopen it in read mode, get the lines with lines = f.readlines(), print the count with print(len(lines)) and close it.

Show example solution

# Write three lines with writelines and close
f = open("list.txt", "w", encoding="utf-8")
f.writelines(["apple\n", "pear\n", "cherry\n"])
f.close()
# Reopen, read with readlines, print the count
f = open("list.txt", "r", encoding="utf-8")
lines = f.readlines()
print(len(lines))
f.close()

Test yourself

Match the writing methods

write

Writes one string
writelines

Writes a list of strings
read

Reads all content
close

Closes the file
Does writelines add \n between items?
- Yes, it adds one automatically between each
- No, it only writes the strings in order
- Only to the last string
- Only to the first string
Show answer

No, it only writes the strings in order — writelines only writes the strings in order; you add the \n yourself.
Complete the write method
```
f.____("Hello
")
```
Show answer
```
f.write("Hello
")
```

Next lesson: with statement

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies