Small Standard Library Projects

URL Query Builder

urllib.parse can build and inspect URL query strings without making network requests.

URL encoding Encoding turns query parameters into text that is safe to place after `?` in a URL.

URL Query Builder

page
url_query_builder.py
Replay: real traced execution (multi-file project)
from urllib.parse import urlencode, urlparse, parse_qs

page = 2

params = {
    "q": "python trace",
    "page": str(page),
    "sort": "recent",
}

query = urlencode(params)
url = "https://example.com/search?" + query
parsed = urlparse(url)
values = parse_qs(parsed.query)

print("path=" + parsed.path)
print("query=" + query)
print("page=" + values["page"][0])

from urllib.parse import urlencode, urlparse, parse_qs

page = 1

params = {
    "q": "python trace",
    "page": str(page),
    "sort": "recent",
}

query = urlencode(params)
url = "https://example.com/search?" + query
parsed = urlparse(url)
values = parse_qs(parsed.query)

print("path=" + parsed.path)
print("query=" + query)
print("page=" + values["page"][0])

from urllib.parse import urlencode, urlparse, parse_qs

page = 5

params = {
    "q": "python trace",
    "page": str(page),
    "sort": "recent",
}

query = urlencode(params)
url = "https://example.com/search?" + query
parsed = urlparse(url)
values = parse_qs(parsed.query)

print("path=" + parsed.path)
print("query=" + query)
print("page=" + values["page"][0])

  1. page ← 2, params ← {'q': 'python trace', 'page': '2', 'sort': 'recent'}

    3page→ 2 = 2  #@page=1, 545params→ {'q': 'python trace', 'page': '2', 'sort': 'recent'} = {6    "q": "python trace",7    "page": str(page2),8    "sort": "recent",9}1011query→ q=python+trace&page=2&sort=recent = urlencode(params{'q': 'python trace', 'page': '2', 'sort': 'recent'})12url→ https://example.com/search?q=python+trace&page=2&sort=recent = "https://example.com/search?" + queryq=python+trace&page=2&sort=recent13parsed→ ParseResult(scheme='https', netloc='example.com', path='/search', params='', query='q=python+trace&page=2&sort=recent', fragment='') = urlparse(urlhttps://example.com/search?q=python+trace&page=2&sort=recent)14values→ {'q': ['python trace'], 'page': ['2'], 'sort': ['recent']} = parse_qs(parsed.queryq=python+trace&page=2&sort=recent)1516print("path=" + parsed.path/search)17print("query=" + queryq=python+trace&page=2&sort=recent)18print("page=" + values["page"][0]2)
    outputpath=/search
query=q=python+trace&page=2&sort=recent
page=2

  1. page ← 1, params ← {'q': 'python trace', 'page': '1', 'sort': 'recent'}

    3page→ 1 = 145params→ {'q': 'python trace', 'page': '1', 'sort': 'recent'} = {6    "q": "python trace",7    "page": str(page1),8    "sort": "recent",9}1011query→ q=python+trace&page=1&sort=recent = urlencode(params{'q': 'python trace', 'page': '1', 'sort': 'recent'})12url→ https://example.com/search?q=python+trace&page=1&sort=recent = "https://example.com/search?" + queryq=python+trace&page=1&sort=recent13parsed→ ParseResult(scheme='https', netloc='example.com', path='/search', params='', query='q=python+trace&page=1&sort=recent', fragment='') = urlparse(urlhttps://example.com/search?q=python+trace&page=1&sort=recent)14values→ {'q': ['python trace'], 'page': ['1'], 'sort': ['recent']} = parse_qs(parsed.queryq=python+trace&page=1&sort=recent)1516print("path=" + parsed.path/search)17print("query=" + queryq=python+trace&page=1&sort=recent)18print("page=" + values["page"][0]1)
    outputpath=/search
query=q=python+trace&page=1&sort=recent
page=1

  1. page ← 5, params ← {'q': 'python trace', 'page': '5', 'sort': 'recent'}

    3page→ 5 = 545params→ {'q': 'python trace', 'page': '5', 'sort': 'recent'} = {6    "q": "python trace",7    "page": str(page5),8    "sort": "recent",9}1011query→ q=python+trace&page=5&sort=recent = urlencode(params{'q': 'python trace', 'page': '5', 'sort': 'recent'})12url→ https://example.com/search?q=python+trace&page=5&sort=recent = "https://example.com/search?" + queryq=python+trace&page=5&sort=recent13parsed→ ParseResult(scheme='https', netloc='example.com', path='/search', params='', query='q=python+trace&page=5&sort=recent', fragment='') = urlparse(urlhttps://example.com/search?q=python+trace&page=5&sort=recent)14values→ {'q': ['python trace'], 'page': ['5'], 'sort': ['recent']} = parse_qs(parsed.queryq=python+trace&page=5&sort=recent)1516print("path=" + parsed.path/search)17print("query=" + queryq=python+trace&page=5&sort=recent)18print("page=" + values["page"][0]5)
    outputpath=/search
query=q=python+trace&page=5&sort=recent
page=5