Dart Beginner Lesson 7 of 115 4 min read

Dart vs Python: Differences, Code Comparison and Which to Learn

Dart vs Python compared with side-by-side code: syntax, types, null safety, lists, classes, async, speed and jobs. Find out which language to learn first.

By Santosh Adhikari · Updated October 16, 2026

Python is the most popular first language for data science, automation and scripting. Dart is the language of Flutter, used to build apps for Android, iOS, web and desktop from one codebase. If you know Python, you already understand most of Dart’s ideas. This page shows the same code in both languages.

At a glance

Hello world and variables

# Python
name = "Asha"
age = 21
print(f"{name} is {age}")

void main() {
  var name = 'Asha';   // type inferred: String
  int age = 21;        // or write the type
  print('$name is $age');
}

Asha is 21

Dart code lives in functions; a program starts at main(). Every statement ends with ;. String interpolation uses $ instead of Python’s f-strings.

Types catch mistakes early

age = 21
age = "twenty-one"   # Python allows this

void main() {
  var age = 21;
  // age = 'twenty-one';  // compile error: a String can't be assigned to an int
  age += 1;
  print(age);
}

22

In Dart, the editor underlines the mistake before you run anything. See variables and data types.

None vs null

String? findCity(String name) => name == 'Asha' ? 'Kathmandu' : null;

void main() {
  print(findCity('Asha') ?? 'unknown');
  print(findCity('Ravi') ?? 'unknown');
}

Kathmandu
unknown

Python’s x if x is not None else default becomes x ?? default. Dart will not let you use a String? as a String until you handle the null case. See null safety.

if, loops and ranges

for i in range(1, 4):
    if i % 2 == 0:
        print(i, "even")
    else:
        print(i, "odd")

void main() {
  for (var i = 1; i < 4; i++) {
    if (i % 2 == 0) {
      print('$i even');
    } else {
      print('$i odd');
    }
  }
}

1 odd
2 even
3 odd

Python’s elif is else if in Dart. There is no range(); use a classic for loop or List.generate. See if else and loops.

Lists and dictionaries

nums = [1, 2, 3, 4]
squares = [n * n for n in nums if n % 2 == 0]
ages = {"Asha": 21, "Ravi": 25}

void main() {
  final nums = [1, 2, 3, 4];
  final squares = [for (final n in nums) if (n.isEven) n * n];
  final ages = {'Asha': 21, 'Ravi': 25};

  print(squares);
  print(ages['Ravi']);
  print(nums.where((n) => n > 2).toList());
}

[4, 16]
25
[3, 4]

A Python list is a Dart List, a dict is a Map, and a set is a Set. Dart even has list comprehensions: [for (...) if (...) value]. See lists, maps and collection if and for.

Functions

def greet(name, greeting="Hello"):
    return f"{greeting}, {name}!"

String greet(String name, {String greeting = 'Hello'}) => '$greeting, $name!';

void main() {
  print(greet('Asha'));
  print(greet('Ravi', greeting: 'Namaste'));
}

Hello, Asha!
Namaste, Ravi!

Python keyword arguments map to Dart named parameters in { }. See function parameters.

Classes

class Dog:
    def __init__(self, name):
        self.name = name
    def bark(self):
        return f"{self.name} says woof"

class Dog {
  final String name;
  Dog(this.name);

  String bark() => '$name says woof';
}

void main() {
  final dog = Dog('Bruno');
  print(dog.bark());
}

Bruno says woof

No self, no __init__: Dog(this.name) is the constructor. Fields starting with _ are private to the file, like Python’s _name convention but enforced. See classes and objects.

async and await

Both languages use async and await. Python’s coroutine is Dart’s Future.

Future<String> download() async {
  await Future.delayed(const Duration(milliseconds: 500));
  return 'data ready';
}

Future<void> main() async {
  print('Start');
  print(await download());
}

Start
data ready

Dart has no asyncio.run(): the event loop is built in. See the async and await lesson.

Errors

void main() {
  try {
    print(int.parse('abc'));
  } on FormatException catch (e) {
    print('Not a number: ${e.source}');
  } finally {
    print('done');
  }
}

Not a number: abc
done

Python’s except ValueError as e becomes on FormatException catch (e). See exceptions.

Which should you learn?

• You want to build mobile apps for Android and iOS, or desktop apps: learn Dart and then Flutter.
• You want data science, machine learning or AI: learn Python.
• You want automation and small scripts: both work; Python has more ready-made libraries.
• You already know Python: you can learn Dart in a week or two. Follow the Dart and Flutter roadmap and move quickly through the first stage.

Both languages are free, well paid and in demand in the USA, Canada, Europe, Australia, India and Nepal. Many developers use Python for back-end and data work and Dart for the app on top. Also see Dart vs JavaScript.