The Faker library enables the creation of realistic synthetic data for testing, prototyping, and anonymization tasks in Python applications.

Installation

Installl via pip:

pip install Faker

Basic Usage

Instantiate a generator using either the Faker class or the legacy Factory:

from faker import Faker
fake = Faker()

print(fake.name())        # e.g., 'Li Wei'
print(fake.address())     # e.g., 'Room 802, No. 15 Beijing Road, Shanghai'
print(fake.text())        # Random paragraph in Chinese

Each method call returns a new random value. The generator supports localization—use 'zh_CN' for Chinese data:

fake_cn = Faker('zh_CN')

Data Categories and Examples

Addresses

fake.city()              # 'Hangzhou'
fake.street_address()    # 'No. 205 Nanjing Road'
fake.postcode()          # '200001'
fake.latitude()          # Decimal('31.2304')

Person Details

fake.name()              # 'Zhang Min'
fake.first_name_male()   # 'Jian'
fake.last_name_female()  # 'Wang'

Barcodes

fake.ean13()             # '6901234567892'
fake.ean(length=8)       # '69012345'

Colors

fake.hex_color()         # '#a3c14b'
fake.color_name()        # 'Crimson'

Companies

fake.company()           # 'FutureLink Digital Technology Ltd.'
fake.company_suffix()    # 'Group Co., Ltd.'

Credit Cards

fake.credit_card_number()      # '4532123456789012'
fake.credit_card_expire()      # '09/28'
fake.credit_card_full()        # Full formatted card info

Dates and Times

fake.date_this_year()          # datetime.date(2024, 5, 12)
fake.iso8601()                 # '2008-07-14T13:45:22'
fake.unix_time()               # 1256789012

Internet Data

fake.ipv4()                    # '192.168.1.105'
fake.email()                   # 'li.xiaoming@example.com'
fake.url()                     # 'http://www.chen.org/'
fake.user_agent()              # Browser user agent string

Text Generation (Lorem Ipsum)

fake.sentence()                # '系统支持用户登录功能。'
fake.paragraph()               # Multi-sentence Chinese paragraph
fake.words(5)                  # ['数据', '分析', '模型', '结果', '验证']

Miscellaneous

fake.password()                # 'Kx!9@mQz#Lp2'
fake.uuid4()                   # 'f47ac10b-58cc-4372-a567-0e02b2c3d479'
fake.boolean()                 # True or False
fake.language_code()           # 'zh'

Phone Numbers

fake.phone_number()            # '13812345678'

Python Objects

fake.pyint()                   # 42
fake.pystr(max_chars=10)       # 'aB3xY9qLmN'
fake.pylist(nb_elements=3)     # Mixed-type list
fake.pydict(nb_elements=2)     # {'key1': 'value', 'key2': 123}

User Profiles

fake.profile()                 # Dict with name, address, job, etc.
fake.simple_profile(sex='F')   # Minimal profile with gender constraint

Chinese ID Numbers (SSN)

fake.ssn()                     # '310101199003072316' (18-digit)

Browser and Platform Strings

fake.chrome()                  # Chrome UA string
fake.windows_platform_token()  # 'Windows 10'
fake.mac_processor()           # 'Intel'

Custom Providers

Extand functionality by creating custom providers:

from faker import Faker
from faker.providers import BaseProvider

class BookProvider(BaseProvider):
    def book_title(self):
        titles = ['Data Engineering', 'Python Tricks', 'Cloud Architecture']
        return self.random_element(titles)

fake = Faker()
fake.add_provider(BookProvider)
print(fake.book_title())  # e.g., 'Cloud Architecture'

Reproducible Results

Set a seed to generate consistant output across runs:

fake = Faker()
fake.seed_instance(12345)
print(fake.name())  # Always 'Chen Yifan' with this seed

Command-Line Interface

Generate data directly in the terminal:

# Generate one Chinese address
faker -l zh_CN address

# Output three names separated by semicolons
faker -r 3 -s ';' name

# Get only ssn and name from profile
faker profile ssn name

Common CLI options:

• -l <locale>: Set language (e.g., zh_CN)
• -r <count>: Repeat output N times
• -s <sep>: Append separator after each result
• -o <file>: Write output to file