Querystring Parser

from querystring_parser import parser
from querystring_parser import builder

from querystring_parser.parser import parse, MalformedQueryStringError
from querystring_parser.builder import build

from querystring_parser import parser

# Parse a query string with nested parameters
query_string = "section[1]['words'][2]=a&section[0]['words'][2]=a&section[0]['words'][2]=b"
result = parser.parse(query_string)

# Output: {u'section': {0: {u'words': {2: [u'a', u'b']}}, 1: {u'words': {2: u'a'}}}}
print(result)

# Convert back to query string
from querystring_parser import builder
rebuilt_query = builder.build(result)
print(rebuilt_query)

def parse(query_string, unquote=True, normalized=False, encoding=DEFAULT_ENCODING):
    """
    Parse query string into nested dictionary structure.
    
    Parameters:
    - query_string (str|bytes): Query string to parse
    - unquote (bool): Whether to URL-decode the query string (default: True)
    - normalized (bool): Convert numeric dict keys to proper lists (default: False)
    - encoding (str|None): Encoding for decoding keys/values (default: DEFAULT_ENCODING)
    
    Returns:
    dict: Nested dictionary representing parsed query string
    
    Raises:
    MalformedQueryStringError: When query string is malformed
    """

from querystring_parser.parser import parse

# Basic parsing
result = parse("name=John&age=30")
# Returns: {'name': 'John', 'age': '30'}

# Nested structures
result = parse("user[name]=John&user[details][age]=30")
# Returns: {'user': {'name': 'John', 'details': {'age': '30'}}}

# Array handling
result = parse("items[0]=apple&items[1]=banana")
# Returns: {'items': {0: 'apple', 1: 'banana'}}

# Normalized output (converts numeric keys to lists)
result = parse("items[0]=apple&items[1]=banana", normalized=True)
# Returns: {'items': ['apple', 'banana']}

# Custom encoding
result = parse("name=%D8%B9%D9%84%DB%8C", encoding='utf-8')
# Returns: {'name': 'علی'}

# Handle bytes input
result = parse(b"name=John&age=30")
# Returns: {'name': 'John', 'age': '30'}

def build(item, encoding=None):
    """
    Convert nested dictionary/list structure to query string format.
    
    Parameters:
    - item (dict|list): Dictionary or list to convert to query string
    - encoding (str|None): Optional encoding for URL encoding (default: None)
    
    Returns:
    str: Query string representation of the input structure
    """

from querystring_parser.builder import build

# Basic dictionary
data = {'name': 'John', 'age': '30'}
result = build(data)
# Returns: "name=John&age=30"

# Nested structures
data = {'user': {'name': 'John', 'details': {'age': '30'}}}
result = build(data)
# Returns: "user[name]=John&user[details][age]=30"

# Lists and arrays
data = {'items': ['apple', 'banana']}
result = build(data)
# Returns: "items=apple&items=banana"

# Mixed nested structures
data = {
    'section': {
        0: {'words': {2: ['a', 'b']}},
        1: {'words': {2: 'c'}}
    }
}
result = build(data)
# Returns: "section[0][words][2]=a&section[0][words][2]=b&section[1][words][2]=c"

# Custom encoding
data = {'name': 'علی'}
result = build(data, encoding='utf-8')
# Returns: "name=%D8%B9%D9%84%DB%8C"

class MalformedQueryStringError(Exception):
    """
    Raised when query string cannot be parsed due to malformed syntax.
    
    Common causes:
    - Missing equals sign in key-value pairs
    - Unclosed bracket notation
    - Invalid bracket syntax
    """

from querystring_parser.parser import parse, MalformedQueryStringError

try:
    # This will raise an exception due to missing equals sign
    result = parse("name&age=30", unquote=False)
except MalformedQueryStringError as e:
    print(f"Failed to parse query string: {e}")

try:
    # This will raise an exception due to unclosed bracket
    result = parse("section[0[words]=value", unquote=False)
except MalformedQueryStringError as e:
    print(f"Failed to parse query string: {e}")

# Module constants
DEFAULT_ENCODING = 'utf-8'  # On Python 2, None on Python 3

# Helper functions (internal but potentially useful)
def has_variable_name(s):
    """Check if string has variable name before bracket notation."""

def more_than_one_index(s, brackets=2):
    """Search for multiple sets of bracket pairs."""

def get_key(s):
    """Extract key from between brackets, removing quotes."""

def is_number(s):
    """Check if string represents a number (for array indices)."""

def parser_helper(key, val):
    """Recursive helper for main parse function."""