Python expandtabs() Method

Beginner
5 min read
Updated: Nov 2026
3 examples
String
Decorative image with the word EXPANDTABS

Definition

In Python, expandtabs() returns a new string where each tab (\t) becomes spaces up to the next tab stop.

tabsize is optional and defaults to 8. The number of spaces depends on column position, not a fixed count.

Syntax

Call expandtabs on the string. Start with this line.

python
aligned = text.expandtabs(4)
CallWhat it does
"a\tb".expandtabs(8)Expands the tab to the next stop.
"a\tb".expandtabs(4)Uses tab stops every 4 columns.

Newlines reset the column counter for the next line.

Library declarations
python
str.expandtabs(tabsize=8) → str

Parameters

ParameterDescription
tabsizeOptional. Spaces between tab stops. Default 8.

Return Value

Return ValueDescription
strA new string with tabs expanded to spaces.

Python Examples

Example 1 — Default Tab Size

Expand tabs with the default stop width of 8 and prove the original string stays unchanged.

python
original = "Name\tAge\tCity"
result = original.expandtabs()

print(repr(original))
print(repr(result))

How It Works

  1. Store tabs. original still holds real \t characters.
  2. Default size. expandtabs() uses tabsize=8.
  3. Align columns. Each tab adds enough spaces to reach the next stop of 8.
  4. Original untouched. Immutability keeps the tab characters in original.

Example 2 — Custom tabsize

Smaller stops pack columns tighter. Notice how space count depends on current column length.

python
print(repr("A\tB".expandtabs(4)))
print(repr("ABCD\tE".expandtabs(4)))

How It Works

  1. Short prefix. "A" ends at column 1 → tab needs 3 spaces to reach 4.
  2. Longer prefix. "ABCD" ends at column 4 → already on a stop, so tab adds 4 spaces to reach 8.
  3. Same tabsize. Both calls use 4, but space counts differ.
  4. Column math. Spaces = tabsize - (column % tabsize).

Example 3 — expandtabs() vs replace()

Fixed replacement cannot align columns the way tab stops do.

python
row = "A\tB"

print("expandtabs:", repr(row.expandtabs(4)))
print("replace:   ", repr(row.replace("\t", "    ")))

How It Works

  1. Same input. Both start from "A\tB".
  2. expandtabs(4). Inserts 3 spaces to hit column 4 → "A B".
  3. replace. Always inserts exactly 4 spaces → "A B".
  4. Pick by goal. Column alignment → expandtabs; fixed swap → replace.

Frequently Asked Questions

It replaces tabs with spaces aligned to tab stops.
string.expandtabs(tabsize=8). tabsize is optional.
No. It returns a new string.
replace() uses a fixed space count. expandtabs() aligns to columns.
When displaying or cleaning tab-separated text before printing.

Next: find()

Learn how to search for a substring and get its index.

find() →

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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