Base64 Encode Python — b64encode() Guide

import base64

# Koda API-inloggningsuppgifter för en HTTP Basic Auth-header
service_id = "deploy-svc"
api_key    = "sk-prod-9f2a1c3e8b4d"

credential_bytes   = f"{service_id}:{api_key}".encode("utf-8")
encoded_bytes      = base64.b64encode(credential_bytes)
encoded_str        = encoded_bytes.decode("ascii")  # bytes → str

print(encoded_str)
# ZGVwbG95LXN2Yzpzay1wcm9kLTlmMmExYzNlOGI0ZA==

import urllib.request

req = urllib.request.Request("https://api.internal/v1/deployments")
req.add_header("Authorization", f"Basic {encoded_str}")
# Headervärde: Basic ZGVwbG95LXN2Yzpzay1wcm9kLTlmMmExYzNlOGI0ZA==

import base64
import json

# Koda strukturerad serverkonfiguration för en miljövariabel
server_config = {
    "host":           "db-primary.eu-west-1.internal",
    "port":           5432,
    "database":       "analytics_prod",
    "max_connections": 150,
    "ssl": {
        "mode":          "verify-full",
        "cert_path":     "/etc/ssl/certs/db-client.crt",
        "reject_self_signed": True,
    },
}

config_json    = json.dumps(server_config, sort_keys=True)
encoded_bytes  = base64.b64encode(config_json.encode("utf-8"))
encoded_str    = encoded_bytes.decode("ascii")

print(encoded_str[:60] + "...")
# eyJkYXRhYmFzZSI6ICJhbmFseXRpY3NfcHJvZCIsICJob3N0IjogImRi...

# Avkoda och verifiera tur-retur
decoded_json   = base64.b64decode(encoded_str).decode("utf-8")
restored       = json.loads(decoded_json)

print(restored["host"])            # db-primary.eu-west-1.internal
print(restored["ssl"]["mode"])     # verify-full

import base64

# Koda flerspråkigt innehåll — visningsnamn från en internationell plattform
user_names = [
    "Erik Lindqvist",       # Svenskt — ASCII
    "田中太郎",              # CJK-ideogram — 3 bytes per tecken i UTF-8
    "Мария Соколова",       # Kyrilliska — U+041C och högre
    "Anna Svensson",        # Svenskt — ASCII
]

for name in user_names:
    encoded = base64.b64encode(name.encode("utf-8")).decode("ascii")
    decoded = base64.b64decode(encoded).decode("utf-8")

    print(f"Original  : {name}")
    print(f"Kodad     : {encoded}")
    print(f"Tur-retur : {decoded}")
    print(f"Matchar   : {name == decoded}")
    print()

# Original  : Мария Соколова
# Kodad     : 0JzQsNGA0LjRjyDQodC+0LrQvtC70L7QstCw
# Tur-retur : Мария Соколова
# Matchar   : True

import base64
import json

def encode_jwt_segment(data: dict) -> str:
    """Koda en dict som en URL-säker Base64-sträng utan utfyllnad (JWT-format)."""
    json_bytes = json.dumps(data, separators=(",", ":")).encode("utf-8")
    return base64.urlsafe_b64encode(json_bytes).rstrip(b"=").decode("ascii")

def decode_jwt_segment(segment: str) -> dict:
    """Avkoda ett URL-säkert Base64-JWT-segment (hanterar saknad utfyllnad)."""
    # Lägg tillbaka utfyllnad: Base64 kräver att längden är en multipel av 4
    padding  = 4 - len(segment) % 4
    padded   = segment + ("=" * (padding % 4))
    raw      = base64.urlsafe_b64decode(padded)
    return json.loads(raw)

# Bygg en JWT-header och nyttolast
header  = {"alg": "HS256", "typ": "JWT"}
payload = {
    "sub":       "usr_7c3a9f1b2d",
    "workspace": "ws_eu-west-1-prod",
    "role":      "data-engineer",
    "iat":       1741824000,
    "exp":       1741910400,
}

header_segment  = encode_jwt_segment(header)
payload_segment = encode_jwt_segment(payload)

print(header_segment)
# eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9

print(payload_segment)
# eyJzdWIiOiJ1c3JfN2MzYTlmMWIyZCIsIndvcmtzcGFjZSI6IndzX2...

# Verifiera tur-retur
restored = decode_jwt_segment(payload_segment)
print(restored["role"])  # data-engineer

import base64
import json
from pathlib import Path

def encode_file_to_base64(file_path: str) -> str:
    """Läs en binär fil och returnera dess Base64-kodade representation."""
    try:
        raw_bytes = Path(file_path).read_bytes()
        return base64.b64encode(raw_bytes).decode("ascii")
    except FileNotFoundError:
        raise FileNotFoundError(f"Filen hittades inte: {file_path}")
    except PermissionError:
        raise PermissionError(f"Åtkomst nekad vid läsning: {file_path}")

# Bifoga ett TLS-certifikat till ett driftsättningsmanifest
cert_b64 = encode_file_to_base64("./ssl/service-client.crt")

deployment_manifest = {
    "service":     "payment-processor",
    "environment": "production",
    "region":      "eu-west-1",
    "tls": {
        "client_cert":     cert_b64,
        "cert_format":     "base64-pem",
    },
}

# Skriv manifestet — certifikatet är säkert inbäddat som en sträng
with open("./dist/deployment-manifest.json", "w") as f:
    json.dump(deployment_manifest, f, indent=2)

print(f"Certifikat kodat: {len(cert_b64)} tecken")

import base64
import requests  # pip install requests

def fetch_and_encode_binary(url: str, headers: dict | None = None) -> str:
    """Hämta en binär resurs från ett API och returnera den som Base64."""
    response = requests.get(url, headers=headers or {}, timeout=10)
    response.raise_for_status()  # kastar HTTPError för 4xx/5xx

    content_type = response.headers.get("Content-Type", "unknown")
    encoded      = base64.b64encode(response.content).decode("ascii")

    print(f"Content-Type  : {content_type}")
    print(f"Rå storlek    : {len(response.content):,} bytes")
    print(f"Kodad storlek : {len(encoded):,} tecken")
    return encoded

# Exempel: ladda ner en signerad PDF-faktura från ett internt fakturerings-API
invoice_b64 = fetch_and_encode_binary(
    "https://billing.internal/api/v2/invoices/INV-2026-0042/pdf",
    headers={"Authorization": "Bearer eyJhbGc..."},
)

# Bifoga till en aviseringsnyttolast
notification = {
    "recipient_id":  "team-finance",
    "invoice_id":    "INV-2026-0042",
    "attachment": {
        "filename":     "invoice-2026-0042.pdf",
        "content":      invoice_b64,
        "content_type": "application/pdf",
        "encoding":     "base64",
    },
}
print(f"Nyttolast klar: {len(str(notification)):,} tecken")

import base64
import mimetypes
from pathlib import Path

def image_to_data_uri(image_path: str) -> str:
    """Konvertera en bildfil till en Base64 data-URI för inline HTML-inbäddning."""
    path      = Path(image_path)
    mime_type = mimetypes.guess_type(image_path)[0] or "image/octet-stream"
    raw_bytes = path.read_bytes()
    encoded   = base64.b64encode(raw_bytes).decode("ascii")
    return f"data:{mime_type};base64,{encoded}"

# Bädda in produktbilder inline i en HTML-e-postmall
hero_uri      = image_to_data_uri("./assets/product-hero-768px.png")
thumbnail_uri = image_to_data_uri("./assets/product-thumb-128px.webp")

html_fragment = f"""
<img src="{hero_uri}"
     alt="Produktbild"
     width="768" height="432"
     style="display:block;max-width:100%" />
"""

print(f"PNG data-URI börjar med: {hero_uri[:60]}...")
# data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAwAAAAA...

import base64
from pathlib import Path

CHUNK_SIZE = 3 * 1024 * 256  # 786 432 bytes — multipel av 3, ~768 KB per segment

def encode_large_file(input_path: str, output_path: str) -> int:
    """
    Koda en stor binär fil till Base64 utan att ladda den helt i minnet.
    Returnerar antalet skrivna Base64-tecken.
    """
    total_chars = 0
    with open(input_path, "rb") as src, open(output_path, "w") as dst:
        while True:
            chunk = src.read(CHUNK_SIZE)
            if not chunk:
                break
            encoded_chunk = base64.b64encode(chunk).decode("ascii")
            dst.write(encoded_chunk)
            total_chars += len(encoded_chunk)
    return total_chars

# Koda en produktvideo på 300 MB för ett asset-delivery-manifest
chars_written = encode_large_file(
    "./uploads/product-demo-4k.mp4",
    "./dist/product-demo-4k.b64",
)
print(f"Kodat: {chars_written:,} Base64-tecken")
# Kodat: 407 374 184 Base64-tecken

import base64
import json
from pathlib import Path

def encode_assets_to_ndjson(asset_dir: str, output_path: str) -> int:
    """
    Koda alla binära filer i en katalog till ett NDJSON-manifest.
    Varje rad är ett JSON-objekt: {"path": "...", "mime": "...", "data": "<base64>"}
    Returnerar antalet bearbetade filer.
    """
    import mimetypes

    asset_path = Path(asset_dir)
    count = 0

    with open(output_path, "w") as out:
        for file_path in sorted(asset_path.rglob("*")):
            if not file_path.is_file():
                continue
            mime = mimetypes.guess_type(str(file_path))[0] or "application/octet-stream"
            encoded = base64.b64encode(file_path.read_bytes()).decode("ascii")
            record  = {"path": str(file_path.relative_to(asset_path)), "mime": mime, "data": encoded}
            out.write(json.dumps(record) + "\n")
            count += 1

    return count

processed = encode_assets_to_ndjson("./dist/static/", "./dist/asset-bundle.ndjson")
print(f"Kodade {processed} filer till NDJSON-tillgångsbunt")

# ── python -m base64 ───────────────────────────────────────────────────
# Koda en sträng (skicka via stdin)
echo -n "deploy-svc:sk-prod-9f2a1c3e8b4d" | python3 -m base64
# ZGVwbG95LXN2Yzpzay1wcm9kLTlmMmExYzNlOGI0ZA==

# Koda en fil
python3 -m base64 ./ssl/service-client.crt

# Avkoda en Base64-sträng
echo "ZGVwbG95LXN2Yzpzay1wcm9kLTlmMmExYzNlOGI0ZA==" | python3 -m base64 -d

# Avkoda en Base64-fil tillbaka till binär
python3 -m base64 -d ./dist/service-client.b64 > ./restored.crt

# ── Python-enradare — plattformsoberoende, fungerar på Windows ─────────
# Koda en sträng
python3 -c "import base64,sys; print(base64.b64encode(sys.argv[1].encode()).decode())" "my-secret"
# bXktc2VjcmV0

# URL-säker kodning (utan utfyllnad)
python3 -c "import base64,sys; print(base64.urlsafe_b64encode(sys.argv[1].encode()).rstrip(b'=').decode())" "my-secret"
# bXktc2VjcmV0

# Koda en fil inline (resultat på stdout)
python3 -c "import base64,sys; print(base64.b64encode(open(sys.argv[1],'rb').read()).decode())" ./config.json

pip install pybase64

import pybase64
import time

# pybase64 är en drop-in-ersättning — samma funktionssignaturer som stdlib
sample_payload = b"x" * (1024 * 1024)  # 1 MB binär data

# Standardkodning — identisk utdata med base64.b64encode()
encoded = pybase64.b64encode(sample_payload)
decoded = pybase64.b64decode(encoded)
assert decoded == sample_payload

# URL-säker kodning — identisk utdata med base64.urlsafe_b64encode()
url_safe = pybase64.urlsafe_b64encode(sample_payload)

# b64encode_as_string() returnerar str direkt — inget .decode()-anrop behövs
telemetry_event = b'{"event":"page_view","session_id":"sess_3a7f91c2","ts":1741824000}'
encoded_str: str = pybase64.b64encode_as_string(telemetry_event)

print(encoded_str[:48] + "...")
# eyJldmVudCI6InBhZ2VfdmlldyIsInNlc3Npb25faWQi...

# Genomströmningsjämförelse (ungefärlig, varierar beroende på hårdvara)
# stdlib  base64.b64encode(1 MB):   ~80 MB/s
# pybase64.b64encode(1 MB):         ~800 MB/s (SIMD-sökväg på AVX2-CPU)

pip install rich

import base64
import json
from rich import print as rprint
from rich.syntax import Syntax
from rich.console import Console

console = Console()

def decode_and_pretty_print(encoded: str, label: str = "Avkodad nyttolast") -> None:
    """Avkoda en Base64-sträng, tolka som JSON och skriv ut med syntaxmarkering."""
    raw_bytes = base64.b64decode(encoded + "==")  # tolerant utfyllnad
    try:
        parsed  = json.loads(raw_bytes)
        pretty  = json.dumps(parsed, indent=2, ensure_ascii=False)
        syntax  = Syntax(pretty, "json", theme="monokai", line_numbers=False)
        console.rule(f"[bold blue]{label}")
        console.print(syntax)
    except json.JSONDecodeError:
        # Inte JSON — skriv ut råtext
        console.rule(f"[bold yellow]{label} (råtext)")
        rprint(raw_bytes.decode("utf-8", errors="replace"))

# Granska ett JWT-nyttolastsegment från en misslyckad autentiseringsbegäran
jwt_payload_segment = "eyJzdWIiOiJ1c3JfN2MzYTlmMWIyZCIsInJvbGUiOiJkYXRhLWVuZ2luZWVyIiwiZXhwIjoxNzQxOTEwNDAwfQ"
decode_and_pretty_print(jwt_payload_segment, "JWT Payload")