Python string zfill() usage and example

Python string methods

The zfill() method returns a copy of the string, which fills '0' characters on the left.

The syntax of zfill() in Python is:

str.zfill(width)

zfill() parameter

zfill() uses a single character width.

The width specifies the length of the string returned from zfill(), and fills '0' on the left.

zfill() return value

zfill() returns a copy of the string, which is filled with '0' on the left. The length of the returned string depends on the provided width.

• Assuming the initial length of the string is10，and the width it specifies will be15。In this case, zfill() returns a copy of the string, which is filled with five '0' digits on the left.

• Assuming the initial length of the string is10，and the width it specifies will be8.In this case, zfill() will not fill '0' on the left and return a copy of the original string. In this case, the length of the returned string will be10.

Example1：How does zfill() work in Python?

text　=　"program is fun"
print(text.zfill(15))
print(text.zfill(20))
print(text.zfill(10))

When running the program, the output is:

0program is fun
000000program is fun
program is fun

If the string starts with a symbol prefix ('+',-The character prefix at the beginning, then fill '0' digits after the first character prefix.

Example2：How to use zfill() with Sign Prefix?

number　=　"-290"
print(number.zfill(8))
number　=　"+290"
print(number.zfill(8))
text　=　"--random+text"
print(text.zfill(20))

When running the program, the output is:

-0000290
+0000290
-0000000-random+text

Python string methods