v0.40: Create exercises. Challenge the community.

common_letters

Your mission

Implement common_letters, a function that keeps shared characters without duplicates.

See it in action

common_letters("vector", "covered")

Expected result

"vecor"

Your checklist

For your own tracking. Tests grade your code.

Create common_letters.py.
Expose def common_letters(left: str, right: str) -> str:.
Scan left from start to end.
Keep a character only if it also appears in right.
Do not repeat a character that was already kept.
The result order must follow the first appearance order in left.
The comparison is case-sensitive.

More examples

common_letters("mno", "XYZ")

Expected result

""

Constraints

Expected files

common_letters.py

Allowed functions

None. Write every helper yourself.

common_letters

Your mission

Implement common_letters, a function that keeps shared characters without duplicates.

See it in action

common_letters("vector", "covered")

Expected result

"vecor"

Your checklist

For your own tracking. Tests grade your code.

Create common_letters.py.
Expose def common_letters(left: str, right: str) -> str:.
Scan left from start to end.
Keep a character only if it also appears in right.
Do not repeat a character that was already kept.
The result order must follow the first appearance order in left.
The comparison is case-sensitive.

More examples

common_letters("mno", "XYZ")

Expected result

""

Constraints

Expected files

common_letters.py

Allowed functions

None. Write every helper yourself.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Shared characters in left orderWaiting

02Deduplicates repeated charactersWaiting

03No common charactersWaiting

04Empty left stringWaiting

05Empty right stringWaiting

06Case-sensitive comparisonWaiting

07First appearance orderWaiting

common_letters

Your mission

Implement common_letters, a function that keeps shared characters without duplicates.

See it in action

common_letters("vector", "covered")

Expected result

"vecor"

Your checklist

For your own tracking. Tests grade your code.

Create common_letters.py.
Expose def common_letters(left: str, right: str) -> str:.
Scan left from start to end.
Keep a character only if it also appears in right.
Do not repeat a character that was already kept.
The result order must follow the first appearance order in left.
The comparison is case-sensitive.

More examples

common_letters("mno", "XYZ")

Expected result

""

Constraints

Expected files

common_letters.py

Allowed functions

None. Write every helper yourself.

v0.40: Create exercises. Challenge the community.

Meet Studio →

common_letters

Your mission

Implement common_letters, a function that keeps shared characters without duplicates.

See it in action

common_letters("vector", "covered")

Expected result

"vecor"

Your checklist

For your own tracking. Tests grade your code.

Create common_letters.py.
Expose def common_letters(left: str, right: str) -> str:.
Scan left from start to end.
Keep a character only if it also appears in right.
Do not repeat a character that was already kept.
The result order must follow the first appearance order in left.
The comparison is case-sensitive.

More examples

common_letters("mno", "XYZ")

Expected result

""

Constraints

Expected files

common_letters.py

Allowed functions

None. Write every helper yourself.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Shared characters in left orderWaiting

02Deduplicates repeated charactersWaiting

03No common charactersWaiting

04Empty left stringWaiting

05Empty right stringWaiting

06Case-sensitive comparisonWaiting

07First appearance orderWaiting