Field types and constraints in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a string field with a maximum length of 50 characters.

FastAPI

from pydantic import BaseModel, Field

class User(BaseModel):
    name: str = Field(max_length=[1])

Drag options to blanks, or click blank then click option'

A50

B100

C0

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using min_length instead of max_length

Setting length to 0 which means no characters allowed

The max_length parameter limits the string length to 50 characters.

2fill in blank

medium

Complete the code to declare an integer field that must be greater than or equal to 18.

FastAPI

from pydantic import BaseModel, Field

class User(BaseModel):
    age: int = Field(ge=[1])

Drag options to blanks, or click blank then click option'

A1

B0

C21

D18

Attempts:

3 left

💡 Hint

Common Mistakes

Using gt instead of ge

Setting the value too low like 0

The ge parameter means "greater than or equal to". Setting it to 18 enforces the minimum age.

3fill in blank

hard

Fix the error in the code by completing the field declaration to require a string with a minimum length of 3.

FastAPI

from pydantic import BaseModel, Field

class Product(BaseModel):
    code: str = Field(min_length=[1])

Drag options to blanks, or click blank then click option'

A1

B0

C3

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using max_length instead of min_length

Setting the value too low like 0 or 1

The min_length parameter sets the minimum number of characters required. Here, 3 ensures the string is at least 3 characters long.

4fill in blank

hard

Fill both blanks to declare a float field that must be between 0.0 and 100.0 inclusive.

FastAPI

from pydantic import BaseModel, Field

class Score(BaseModel):
    value: float = Field(ge=[1], le=[2])

Drag options to blanks, or click blank then click option'

A0.0

B100.0

C50.0

D1.0

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up ge and le

Using integer values instead of floats

The ge parameter sets the minimum value, and le sets the maximum value. Here, the score must be between 0.0 and 100.0.

5fill in blank

hard

Fill both blanks to create a string field that is required, has a minimum length of 5, and a maximum length of 20.

FastAPI

from pydantic import BaseModel, Field

class Account(BaseModel):
    username: str = Field(..., min_length=[1], max_length=[2])

Drag options to blanks, or click blank then click option'

Arequired=True

B5

C20

Dnullable=False

Attempts:

3 left

💡 Hint

Common Mistakes

Using invalid arguments like required=True or nullable=False

Setting the length values too low like 0

The min_length and max_length set the string length limits. The ... means the field is required.