LangChain installation and setup in Prompt Engineering / GenAI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to install LangChain using pip.

Prompt Engineering / GenAI

pip install [1]

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

Ascikit-learn

Bnumpy

Ctensorflow

Dlangchain

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to install unrelated packages like numpy or tensorflow.

Misspelling the package name.

To install LangChain, use pip install langchain. This command downloads and installs the LangChain library.

2fill in blank

medium

Complete the code to import the main LangChain class for building chains.

Prompt Engineering / GenAI

from langchain.chains import [1]

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ALLMChain

BChain

CTextChain

DModelChain

Attempts:

3 left

💡 Hint

Common Mistakes

Using a class name that does not exist like Chain or TextChain.

Confusing the class name with other LangChain components.

The main class to build language model chains in LangChain is LLMChain. Import it from langchain.chains.

3fill in blank

hard

Fix the error in the code to create a LangChain LLMChain with an OpenAI model.

Prompt Engineering / GenAI

from langchain.llms import OpenAI
llm = OpenAI(model_name=[1])
chain = LLMChain(llm=llm, prompt=prompt)

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

A'text-davinci-003'

B'gpt-3.5-turbo'

C'openai-gpt'

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the model name string.

Using an invalid or unsupported model name.

The model_name parameter requires a string with the exact model name. 'text-davinci-003' is a valid OpenAI model name for LangChain.

4fill in blank

hard

Fill both blanks to create a prompt template and initialize an LLMChain with it.

Prompt Engineering / GenAI

from langchain.prompts import [1]
prompt = [2](template="Hello, {{name}}!")
chain = LLMChain(llm=llm, prompt=prompt)

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

APromptTemplate

BPrompt

CTemplatePrompt

DChainPrompt

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect class names like Prompt or ChainPrompt.

Importing one name but using another.

The class to create prompt templates in LangChain is PromptTemplate. Use it to define the prompt with placeholders.

5fill in blank

hard

Fill all three blanks to run the chain and print the output.

Prompt Engineering / GenAI

input_data = [1](name="Alice")
result = chain.[2](input_data)
print(result[[3]])

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

Adict

Binvoke

C'text'

Dexecute

Attempts:

3 left

💡 Hint

Common Mistakes

Passing input as a list or other type instead of dict.

Using wrong method names like execute instead of invoke.

Accessing result with wrong keys.

Input data should be a dictionary. Use chain.invoke() to execute the chain. The result is accessed by the key 'text'.

Practice

1. What is the primary command to install LangChain using Python's package manager?

easy

A. pip install langchain

B. python langchain install

C. install langchain pip

D. pip get langchain

Solution

1. Step 1: Understand Python package installation

   Python packages are installed using the pip install package_name command.

2. Step 2: Identify the correct LangChain installation command

   The correct command to install LangChain is pip install langchain.

3. Final Answer:

   pip install langchain -> Option A

4. Quick Check:

   pip install langchain = A [OK]

Hint: Remember: pip install + package name installs it [OK]

Common Mistakes:

• Using 'python langchain install' instead of pip
• Swapping order of words in command
• Using 'pip get' which is invalid

2. Which of the following commands correctly installs LangChain with optional extras for OpenAI support?

easy

A. pip install langchain --extras openai

B. pip install langchain-openai

C. pip install langchain[openai]

D. pip install langchain(openai)

Solution

1. Step 1: Understand optional extras syntax in pip

   Optional extras are added using square brackets after the package name, like package[extra].

2. Step 2: Identify correct syntax for LangChain with OpenAI extras

   The correct command is pip install langchain[openai].

3. Final Answer:

   pip install langchain[openai] -> Option C

4. Quick Check:

   Optional extras use brackets = C [OK]

Hint: Use brackets [] for extras in pip install [OK]

Common Mistakes:

• Using parentheses instead of brackets
• Trying to pass extras with --extras flag
• Installing a non-existent package name

3. What will be the output of this Python code after installing LangChain correctly?

import langchain
print(langchain.__version__)

medium

A. SyntaxError due to incorrect import

B. Raises ImportError because langchain is not installed

C. Prints 'langchain' as a string

D. Prints the installed LangChain version like '0.0.200'

Solution

1. Step 1: Understand import behavior after installation

   If LangChain is installed, importing it succeeds without error.

2. Step 2: Accessing __version__ attribute

   LangChain exposes its version via langchain.__version__, which prints the version string.

3. Final Answer:

   Prints the installed LangChain version like '0.0.200' -> Option D

4. Quick Check:

   Installed package import prints version = D [OK]

Hint: Import then print __version__ to check package version [OK]

Common Mistakes:

• Expecting import to print package name
• Confusing ImportError with SyntaxError
• Not installing before running code

4. You run pip install langchain but get an error saying 'command not found'. What is the most likely fix?

medium

A. Change command to pip get langchain

B. Use python -m pip install langchain instead

C. Restart the computer and try again

D. Install LangChain using conda install langchain

Solution

1. Step 1: Understand 'command not found' error

   This error means the system cannot find the pip command in the current environment.

2. Step 2: Use Python module to run pip

   Running python -m pip install langchain uses Python to call pip directly, avoiding path issues.

3. Final Answer:

   Use python -m pip install langchain instead -> Option B

4. Quick Check:

   Use python -m pip if pip command missing = B [OK]

Hint: Run pip via python -m pip to avoid missing command errors [OK]

Common Mistakes:

• Using invalid pip commands like 'pip get'
• Assuming restart fixes command not found
• Trying conda without conda environment

5. You want to install LangChain and also include support for OpenAI and HuggingFace integrations. Which command correctly installs both optional extras?

hard

A. pip install langchain[openai,huggingface]

B. pip install langchain[openai] huggingface

C. pip install langchain --extras openai huggingface

D. pip install langchain(openai,huggingface)

Solution

1. Step 1: Understand multiple extras syntax in pip

   Multiple extras are listed inside one pair of square brackets, separated by commas.

2. Step 2: Identify correct command for multiple extras

   The correct command is pip install langchain[openai,huggingface].

3. Final Answer:

   pip install langchain[openai,huggingface] -> Option A

4. Quick Check:

   Multiple extras use comma inside brackets = A [OK]

Hint: List multiple extras comma-separated inside one bracket [OK]

Common Mistakes:

• Separating extras as separate arguments
• Using parentheses instead of brackets
• Using --extras flag incorrectly