# stringbuilder
URL: /patitas/api/stringbuilder/
Section: api
Description: StringBuilder for O(n) string accumulation.
Adopts kida's proven StringBuilder pattern for efficient HTML output.
Appends to a list, joins once at the end: O(n) total vs O(n²) for
repeated string concatenation.
Thread Safety:
StringBuilder instances are local to each render() call.
No shared mutable state.
Performance:
For a 1000-line document with 500 rendered fragments:
- String concatenation: ~125,000 character copies
- StringBuilder: ~25,000 character copies (5x faster)
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Module
#
`stringbuilder`
StringBuilder for O(n) string accumulation.
Adopts kida's proven StringBuilder pattern for efficient HTML output.
Appends to a list, joins once at the end: O(n) total vs O(n²) for
repeated string concatenation.
Thread Safety:
StringBuilder instances are local to each render() call.
No shared mutable state.
Performance:
For a 1000-line document with 500 rendered fragments:
- String concatenation: ~125,000 character copies
- StringBuilder: ~25,000 character copies (5x faster)
1Class
## Classes
`StringBuilder`
8
▼
Efficient string accumulator.
Appends to a list, joins once at the end.
O(n) total vs O(n²) for re…
Efficient string accumulator.
Appends to a list, joins once at the end.
O(n) total vs O(n²) for repeated string concatenation.
Usage:
```
>>> sb = StringBuilder()
>>> sb.append("")
>>> sb.append("Hello")
>>> sb.append("
")
>>> sb.build()
'Hello
'
```
Thread Safety:
```
Instance is local to each render() call.
No shared mutable state.
```
#### Methods
`append`
1
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
▼
Append a string to the builder.
`def append(self, s: str) -> StringBuilder`
##### Parameters
Name
Type
Description
`s`
`—`
String to append (empty strings are skipped)
##### Returns
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
self for method chaining
`append_line`
1
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
▼
Append a string followed by newline.
`def append_line(self, s: str = '') -> StringBuilder`
##### Parameters
Name
Type
Description
`s`
`—`
String to append (empty = just newline)
Default:`''`
##### Returns
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
self for method chaining
`extend`
1
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
▼
Append multiple strings at once.
`def extend(self, strings: list[str]) -> StringBuilder`
##### Parameters
Name
Type
Description
`strings`
`—`
List of strings to append
##### Returns
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
self for method chaining
`build`
0
`str`
▼
Join all parts into final string.
`def build(self) -> str`
##### Returns
`str`
Concatenated string of all appended parts
`clear`
0
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
▼
Clear all accumulated parts.
`def clear(self) -> StringBuilder`
##### Returns
`StringBuilder (/patitas/api/stringbuilder/#StringBuilder)`
self for method chaining
Internal Methods
3
▼
`__init__`
0
▼
Initialize empty StringBuilder.
`def __init__(self) -> None`
`__len__`
0
`int`
▼
Return number of parts (not total length).
`def __len__(self) -> int`
##### Returns
`int`
`__bool__`
0
`bool`
▼
Return True if any parts have been appended.
`def __bool__(self) -> bool`
##### Returns
`bool`