Python Data Types

Every value in Python has a type. Python picks types from literals like 42 or "hi". Each gray box below is one runnable sample — use the small Try in editor chip to open the IDE with that exact code loaded (?example=…).

1. Numbers — integers and floats

An integer (int) is a whole number. A float (float) has a decimal point. Underscores in literals are only for readability.

count = 7
million = 1_000_000
avg = 9.5

print(count + 2)       # 9
print(type(count))     # <class 'int'>
print(type(avg))       # <class 'float'>

2. Text — strings (str)

Strings hold text. Match your quotes; use \n inside quotes for a newline.

name = "Ada"
emoji = '🐍'
story = "Line one.\nLine two."

print(len(name))
print(name.lower())
print("Hello, " + name)
print(story)

3. Yes / no — booleans (bool)

Only two values: True and False (capital letter first). Comparisons return booleans.

logged_in = True
print(10 > 3)
print("python" == "java")

4. Lists — ordered, changeable

A list keeps items in order. You can append, remove, or replace items.

scores = [88, 92, 79]
scores.append(95)
first = scores[0]

print(scores)
print(len(scores))

5. Tuples — ordered pairs / records

A tuple is like a fixed-length list you usually do not mutate — handy for coordinates.

point = (10, 20)
rgb = (255, 128, 0)

print(point[0], rgb[2])

6. Dictionaries — label → value

A dict maps keys (often strings) to values. Lookup by key is fast and readable.

user = {"name": "Sam", "score": 42}
print(user["name"])
user["score"] = 100

print(list(user.keys()))
print(list(user.values()))

7. None — nothing assigned yet

None means “no useful object here.” Prefer is None when comparing.

answer = None
print(answer is None)

8. Check any value’s type

Use type() while learning what Python stored.

samples = [42, 3.14, "hi", True, [1], (2,), {"k": 3}, None]
for item in samples:
print(repr(item), "->", type(item).__name__)

How this relates to databases (simple picture)

In SQLite (and SQL generally), each column stores one kind of value — numeric, text, blob, etc. In Python you pick types that fit your problem; drivers map Python values into SQL safely.

Practice

Use each snippet chip above, or the compact Try in editor button under the lesson title for the combined playground preset.