Docs: Update stdlib email-errno

Co-Authored-By: Codex <codex@openai.com>

Author: heikkitoivonen

DOCUMENTATION_STATUS.md

@@ -5,12 +5,12 @@ This document tracks the coverage of built-in functions, types, and standard lib
 ## Overview
 
 - **Total Items**: 317 (150 builtins + 167 stdlib modules)
-- **Documented**: 375 (174 builtins + 201 stdlib)
-- **Coverage**: 118.3%
+- **Documented**: 376 (174 builtins + 202 stdlib)
+- **Coverage**: 118.6%
 
 **Note**: Coverage exceeds 100% because comprehensive documentation files (like `exceptions.md`) cover multiple individual items, and we document deprecated/removed modules for historical reference.
 
-Last updated: January 2026 (Python 3.14 audit)
+Last updated: January 27, 2026 (Python 3.14 audit)
 
 ## Built-in Types & Functions
 
@@ -203,7 +203,7 @@ Complete coverage of all built-in functions, types, exceptions, and constants:
 
 ## Standard Library Modules
 
-**Coverage: 120.4% (201/167)**
+**Coverage: 121.0% (202/167)**
 
 All standard library modules are fully documented, including new Python 3.14 modules. Coverage exceeds 100% due to documentation of deprecated/removed modules for historical reference.
 
@@ -305,14 +305,15 @@ All file and I/O modules now documented:
 - ✅ `shutil` - High-level file operations
 - ✅ `tempfile` - Temporary files
 
-### ✅ ALL MODULES COMPLETE (188/188)
+### ✅ ALL MODULES COMPLETE (202/202)
 
 All 100 previously undocumented stdlib modules have been added:
 
-**Utilities & System (18)**
+**Utilities & System (19)**
 - ✅ `ast` - Abstract syntax trees
 - ✅ `dis` - Disassembler for bytecode
 - ✅ `doctest` - Testing via docstrings
+- ✅ `errno` - Error number constants
 - ✅ `getopt` - Command-line option parsing
 - ✅ `gettext` - Internationalization
 - ✅ `keyword` - Python keywords

data/documentation_audit.json

@@ -168,8 +168,8 @@
   },
   "stdlib": {
     "total": 167,
-    "documented": 201,
-    "coverage_percent": 120.4,
+    "documented": 202,
+    "coverage_percent": 121.0,
     "missing": [
       "audit_documentation",
       "cProfile",
@@ -179,7 +179,7 @@
   },
   "summary": {
     "total_items": 317,
-    "total_documented": 375,
-    "overall_coverage_percent": 118.3
+    "total_documented": 376,
+    "overall_coverage_percent": 118.6
   }
 }

docs/stdlib/email.md

@@ -6,6 +6,8 @@ The `email` module provides utilities for constructing and parsing email message
 
 | Operation | Time | Space | Notes |
 |-----------|------|-------|-------|
+| `message_from_bytes()` | O(n) | O(n) | n = byte length |
+| `message_from_binary_file()` | O(n) | O(n) | n = file size |
 | `message_from_string()` | O(n) | O(n) | n = email size |
 | `message_from_file()` | O(n) | O(n) | n = file size |
 | `email.parser.Parser()` | O(n) | O(n) | Parse email |

docs/stdlib/encodings.md

@@ -8,6 +8,9 @@ The `encodings` module provides Python's standard character encoding implementat
 |-----------|------|-------|-------|
 | Get encoding | O(1) | O(1) | Cache lookup |
 | Encode/decode | O(n) | O(n) | n = string length |
+| `normalize_encoding()` | O(n) | O(n) | n = name length |
+| `search_function()` | O(n) | O(1) | Normalizes then looks up |
+| `aliases` lookup | O(1) | O(1) | Dict access |
 
 ## Character Encodings
 

docs/stdlib/ensurepip.md

@@ -7,6 +7,7 @@ The `ensurepip` module bootstraps the pip package installer into Python installa
 | Operation | Time | Space | Notes |
 |-----------|------|-------|-------|
 | `bootstrap()` | O(n) | O(n) | Install pip |
+| `version()` | O(1) | O(1) | Return bundled pip version string |
 | Verify | O(1) | O(1) | Check availability |
 
 ## Bootstrapping pip
@@ -19,6 +20,13 @@ import ensurepip
 # Bootstrap pip - O(n)
 ensurepip.bootstrap()
 
+# Optional arguments (all keyword-only) - O(n)
+ensurepip.bootstrap(
+    upgrade=True,      # upgrade bundled pip
+    default_pip=True,  # install pip even if a "pipX" already exists
+    verbosity=1,       # pass through to pip
+)
+
 # Or from command line:
 # python -m ensurepip
 # python -m ensurepip --upgrade

docs/stdlib/enum.md

@@ -12,6 +12,9 @@ The `enum` module provides a way to define a set of symbolic names (members) bou
 | Iteration `for e in EnumClass` | O(n) | O(1) | n = number of members |
 | `len(EnumClass)` | O(1) | O(1) | Cached member count |
 | `name` / `value` access | O(1) | O(1) | Direct attribute |
+| `auto()` | O(1) | O(1) | Auto-value sentinel |
+| `unique()` | O(n) | O(1) | Validate aliases in class |
+| `verify()` | O(n) | O(1) | Validate member constraints |
 
 ## Enum Basics
 

docs/stdlib/errno.md

@@ -0,0 +1,73 @@
+# errno Module
+
+The `errno` module provides platform-specific error number constants and an `errorcode` mapping
+for converting between numeric error codes and their symbolic names.
+
+## Complexity Reference
+
+| Operation | Time | Space | Notes |
+|-----------|------|-------|-------|
+| Access `E*` constant | O(1) | O(1) | Integer constant lookup |
+| `errorcode[err]` | O(1) | O(1) | Dict lookup for symbolic name |
+| Compare `exc.errno` | O(1) | O(1) | Integer compare |
+
+!!! warning "Platform-dependent constants"
+    `errno` values are OS-dependent. Some constants may be missing or have different numeric
+    values across platforms.
+
+## Common Operations
+
+### Check an `OSError` by errno
+
+```python
+import errno
+
+try:
+    with open("missing.txt", "r") as handle:
+        data = handle.read()
+except OSError as exc:
+    if exc.errno == errno.ENOENT:
+        print("File not found")
+    elif exc.errno == errno.EACCES:
+        print("Permission denied")
+    else:
+        raise
+```
+
+### Map an error code to its name
+
+```python
+import errno
+
+# O(1) lookup
+name = errno.errorcode[errno.ENOENT]  # "ENOENT"
+```
+
+### Use errno in filesystem helpers
+
+```python
+import errno
+import os
+
+try:
+    os.remove("tmp.txt")
+except FileNotFoundError as exc:
+    # FileNotFoundError derives from OSError
+    if exc.errno == errno.ENOENT:
+        pass
+```
+
+## Public Constants
+
+The module exposes many `E*` integer constants such as:
+
+- `EACCES`, `EEXIST`, `EINVAL`, `EIO`, `ENOENT`, `ENOSPC`, `ENOTDIR`, `EPIPE`
+- Socket-related errors like `ECONNRESET`, `ECONNREFUSED`, `ETIMEDOUT`
+
+Use `dir(errno)` to list all constants available on your platform.
+
+## Related Documentation
+
+- [os Module](os.md)
+- [stat Module](stat.md)
+- [pathlib Module](pathlib.md)

mkdocs.yml

@@ -180,6 +180,7 @@ nav:
     - Deque: stdlib/deque.md
     - Defaultdict: stdlib/defaultdict.md
     - Enum: stdlib/enum.md
+    - Errno: stdlib/errno.md
     - Fcntl: stdlib/fcntl.md
     - Filecmp: stdlib/filecmp.md
     - Fileinput: stdlib/fileinput.md