Flowchart in Python

Flowchart Symbols

Flowcharts use a set of standard symbols to represent different types of steps & actions in a process. Here are some of the most common flowchart symbols & what they mean:

1. Oval

The oval shape represents the start or end point of the process. It shows where the flowchart begins & ends.

2. Rectangle

The rectangle shape is used for a process step. It shows a specific action or task that needs to be done.

3. Diamond

The diamond shape represents a decision point. It indicates a place where the process branches into different paths based on a question or condition.

4. Arrow

The arrow symbol shows the flow & direction of the process. It connects the different shapes & shows the order of the steps.

5. Parallelogram

The parallelogram is used for input or output. It represents data that goes into the process or information that comes out.

6. Circle

The circle is used for a connector. It shows a jump from one part of the flowchart to another.

These are just a few examples of the symbols used in flowcharts. There are other less common symbols as well for things like documents, databases & manual operations.

With the help of these standard symbols, flowcharts can be easily understood by anyone who is familiar with them. The symbols help to clearly show what type of step each shape represents in the overall process.

Uses of Flowcharts in Computer Programming/Algorithms

Flowcharts are very useful in the field of computer programming & algorithm design. Here are some of the main ways they are used:

1. Planning & designing programs: Before writing the actual code, programmers often use flowcharts to plan out the logic & structure of a program. The flowchart acts as a blueprint, showing the different parts of the program & how they fit together.
 

2. Visualizing algorithms: Algorithms are step-by-step procedures for solving problems. Flowcharts are a great way to visualize how an algorithm works. Each step of the algorithm is represented by a symbol in the flowchart, making it easier to follow the logic.
 

3. Debugging & troubleshooting: When a program has a bug or error, a flowchart can help identify where the problem is occurring. By tracing through the flowchart step by step, programmers can find the exact point where the issue arises.
 

4. Communicating with team members: In large software projects, flowcharts are useful for communicating ideas between team members. They provide a common language that everyone can understand, regardless of their programming background.
 

5. Documenting programs: Flowcharts serve as a form of documentation for programs. They show how the program works, which can be helpful for future reference or if the program needs to be modified later.
 

6. Teaching & learning: Flowcharts are often used in teaching programming concepts to new learners. They provide a visual way to explain complex ideas & make the learning process more intuitive.

For example : 

Let’s see an example for calculating the average of three numbers, but with proper flowchart symbols:
 

In this flowchart:

• The oval shapes represent the start and end points of the process.
   
• The parallelogram shape is used for the input step, where we get the three numbers from the user.
   
• The rectangle shapes are used for the processing steps, where we calculate the sum and average.
   
• The parallelogram shape is used again for the output step, where we display the calculated average.
   
• The arrows show the flow and direction of the process, connecting the steps in the correct order.
   

This flowchart provides a clear visual representation of the steps involved in calculating the average of three numbers. It's easy to follow the logic from start to finish, and the symbols help to distinguish between the different types of steps (input, processing, output).

When to Use Flowchart?

1. When a process is complex: If a process has many steps, decision points, or possible paths, a flowchart can help break it down and make it easier to understand.

2. When a process needs to be optimized: Flowcharts can help identify inefficiencies, redundancies, or bottlenecks in a process. By visualizing the steps, it's easier to see where improvements can be made.

3. When a process needs to be standardized: If a process needs to be followed consistently by multiple people, a flowchart can serve as a standard reference. It ensures everyone is on the same page and following the same steps.

4. When communicating with non-technical people: Flowcharts are a great way to explain technical processes to people who may not have a background in the field. The visual nature of flowcharts makes them more accessible and easier to grasp.

5. When documenting a process for future reference: Flowcharts serve as a form of documentation. They can be referred back to in the future if there are questions about how a process works or if it needs to be revisited or updated.

6. When troubleshooting a process: If a process isn't working as expected, a flowchart can help identify where the problem is occurring. By going through the flowchart step by step, it's easier to pinpoint the issue.

7. When planning a new process: Before implementing a new process, creating a flowchart can help work out the details and identify potential problems. It's a useful planning tool to ensure the process is well-thought-out before it's put into action.

Types of Flowcharts

There are several types of flowcharts, each serving a different purpose. Here are the main types:

I apologize for the confusion. Here are the types of flowcharts commonly used in Python programming and algorithm design, along with code examples:

1. Algorithm Flowchart

Example: A flowchart showing the algorithm for binary search.

• Python

Python

def binary_search(arr, target):
    low = 0
    high = len(arr) - 1

    while low <= high:
        mid = (low + high) // 2

        if arr[mid] == target:
            return mid
        elif arr[mid] < target:
            low = mid + 1
        else:
            high = mid - 1

    return -1

# Usage example
my_list = [1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
target_value = 7

result = binary_search(my_list, target_value)

if result != -1:
    print(f"Element {target_value} found at index {result}")
else:
    print(f"Element {target_value} not found in the list")

You can also try this code with Online Python Compiler

Run Code

Output

Element 7 found at index 3

2. Program Flowchart

Example: A flowchart showing the flow of a Python program that calculates the factorial of a number.

• Python

Python

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n - 1)

# Input number
num = int(input("Enter a non-negative integer: "))

# Calculate factorial
if num < 0:
    print("Factorial is not defined for negative numbers.")
else:
    result = factorial(num)
    print(f"The factorial of {num} is {result}")

You can also try this code with Online Python Compiler

Run Code

Output

Enter a non-negative integer: 6
The factorial of 6 is 720

3. Function Flowchart

Example: A flowchart showing the flow of a Python function that checks if a given number is prime.

• Python

Python

def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            return False
    return True

# Input number
num = int(input("Enter a positive integer: "))

# Check if prime
if is_prime(num):
    print(f"{num} is a prime number")
else:
    print(f"{num} is not a prime number")

You can also try this code with Online Python Compiler

Run Code

Output

Enter a positive integer: 9
9 is not a prime number

4. Loop Flowchart

Example: A flowchart showing the flow of a Python loop that prints the Fibonacci sequence up to a given number of terms.

• Python

Python

def fibonacci(n):
    if n <= 0:
        return []
    elif n == 1:
        return [0]
    elif n == 2:
        return [0, 1]
    else:
        fib = [0, 1]
        for i in range(2, n):
            fib.append(fib[i-1] + fib[i-2])
        return fib

# Input number of terms
num_terms = int(input("Enter the number of terms: "))

# Generate Fibonacci sequence
fib_sequence = fibonacci(num_terms)

# Output sequence
print("Fibonacci sequence:")
for num in fib_sequence:
    print(num, end=" ")

You can also try this code with Online Python Compiler

Run Code

Output

Enter the number of terms: 5
Fibonacci sequence:
0 1 1 2 3 

Advantages of Flowchart

1. Clarity and Understanding

   - Flowcharts provide a clear, visual representation of a process.

   - They break down complex processes into simple, easy-to-follow steps.

   - This clarity helps in understanding the process better, even for people who are not directly involved in it.
 

2. Effective Communication

   - Flowcharts serve as an excellent communication tool.

   - They can be used to explain a process to others, such as team members, stakeholders, or clients.

   - The visual nature of flowcharts makes it easier to convey ideas and ensure everyone is on the same page.
 

3. Process Improvement

   - Creating a flowchart requires a thorough understanding of the process.

   - During this process, inefficiencies, redundancies, or bottlenecks can be identified.

   - By analyzing the flowchart, improvements can be made to streamline the process and increase efficiency.
 

4. Troubleshooting and Problem Solving:

   - Flowcharts are useful for troubleshooting and problem-solving.

   - If a problem occurs in a process, the flowchart can be followed step by step to identify where the issue lies.

   - This systematic approach can help in pinpointing and resolving problems more quickly.
 

5. Documentation and Reference:

   - Flowcharts serve as a form of documentation for a process.

   - They can be used as a reference point in the future, especially if the process needs to be revisited or modified.

   - Having a flowchart makes it easier for new team members to understand and follow the process.
 

6. Versatility:

   - Flowcharts can be used in a wide range of fields and applications.

   - They are useful in business, engineering, computing, education, and many other areas.

   - Flowcharts can be adapted to suit the specific needs of the process being mapped.
 

7. Encourages Logical Thinking:

   - Creating a flowchart requires logical thinking and step-by-step reasoning.

   - It encourages the creator to think through the process systematically, considering all possible paths and outcomes.

   - This logical approach can be beneficial in many aspects of work and problem-solving.

Disadvantages of Flowchart

1. Oversimplification:

   - Flowcharts tend to simplify processes, which can sometimes lead to important details being left out.

   - Complex processes may have nuances or exceptions that are difficult to represent in a flowchart.

   - Oversimplification can lead to misinterpretation or incorrect assumptions about the process.
 

2. Limited Detail:

   - Flowcharts provide a high-level view of a process, but they may not include all the necessary details.

   - Detailed technical specifications, complex decision rules, or specific instructions may not fit well into a flowchart format.

   - In some cases, additional documentation may be needed to supplement the flowchart.
 

3. Maintenance and Updating:

   - Processes can change over time, requiring the flowchart to be updated.

   - Maintaining and updating flowcharts can be time-consuming, especially for complex processes.

   - If a flowchart is not kept up to date, it can become misleading or inaccurate.

4. Limited Scope:

   - Flowcharts typically focus on a specific process or part of a system.

   - They may not show how the process fits into the bigger picture or interacts with other processes.

   - This limited scope can sometimes lead to a lack of context or understanding of the overall system.
 

5. Interpretation and Ambiguity:

   - While flowcharts aim to be clear and concise, there can still be room for interpretation.

   - Different people may interpret the symbols or flow of the chart differently, leading to confusion or misunderstandings.

   - Ambiguity in the flowchart can lead to inconsistencies in how the process is followed.
 

6. Need for Training:

   - To effectively create and understand flowcharts, some training may be required.

   - People need to be familiar with the standard symbols and conventions used in flowcharting.

   - Without proper training, people may create incorrect or unclear flowcharts, or misinterpret existing ones.
 

7. Not Suitable for All Processes:

   - Some processes may be too complex or dynamic to be effectively represented by a flowchart.

   - Processes that involve a lot of human judgment, creativity, or adaptability may not lend themselves well to the structured nature of flowcharts.

   - In these cases, other tools or methods may be more appropriate for mapping or documenting the process.

Frequently Asked Questions

Can flowcharts be used for non-linear processes?

While flowcharts are best suited for linear processes, they can be adapted for non-linear ones by using connectors and decision points to show alternate paths.

How detailed should a flowchart be?

The level of detail in a flowchart depends on its purpose. An overview flowchart will be less detailed than one used for process analysis or improvement.

Are there any software tools for creating flowcharts?

Yes, there are many software tools available, such as Microsoft Visio, Lucidchart, and Creately, that make it easy to create professional-looking flowcharts.

Conclusion

In this article, we have learned about flowcharts, which are powerful visual tools for representing processes. We discussed the different symbols used in flowcharts, their applications in computer programming and algorithms, and when they are most useful. We also explained the different types of flowcharts, the types of boxes used in their creation, and their advantages and disadvantages.

You can also check out other blogs on Code360.