Python Coding challenge - Day 664| What is the output of the following Python Code?

 

Code Explanation:

1. Importing the NumPy Library

import numpy as np

Loads the NumPy library into the program.

The alias np is used so you can type np instead of numpy for every function call.

2. Creating a NumPy Array

arr = np.array([1, 2, 3, 4, 5])

Creates a NumPy array named arr containing integers [1, 2, 3, 4, 5].

NumPy arrays store elements of the same type and support vectorized operations (fast element-wise math).

3. Making a Boolean Mask

mask = arr <= 3

Checks, for each element in arr, if it is less than or equal to 3.

Returns a Boolean array:

[ True, True, True, False, False ]

True means the element satisfies the condition (<= 3).

4. Selecting & Modifying Elements with the Mask

arr[mask] = arr[mask] ** 2

arr[mask] selects only the elements where mask is True: [1, 2, 3].

arr[mask] ** 2 squares each selected element → [1, 4, 9].

Assigns these squared values back into their original positions in arr.

Now arr becomes:

[1, 4, 9, 4, 5]

5. Accessing the Second-to-Last Element

print(arr[-2])

arr[-2] means second from the end (negative indexing starts from the right).

In [1, 4, 9, 4, 5], the second-to-last element is 4.

Prints:

4

Final Output:

4

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Python Coding Challange - Question with Answer (01120825)

 

Let’s go step by step:

def halve_middle(nums):
 nums[1] /= 2

• This defines a function halve_middle that takes a list nums.

• nums[1] refers to the second element in the list (indexing starts at 0).

• /= 2 means divide the value by 2 and assign the result back to that same position.

• Since / in Python produces a float, the result becomes a floating-point number.

a = [8, 16, 24]

• A list a is created with three numbers: first element 8, second element 16, third element 24.

halve_middle(a)

• The function is called with a as the argument.

• Inside the function, nums refers to the same list object as a (lists are mutable).

• The second element (16) is divided by 2 → 8.0

• The list is now [8, 8.0, 24].

print(a)

• Prints [8, 8.0, 24].

• The change persists because the function modified the original list in place.

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Python Coding Challange - Question with Answer (01110825)

 

Let’s break this down step by step:

---

try:
   d = {"a": 1}
   print(d["b"])
except KeyError:
    print("Key missing")

1️⃣ try:

• This starts a try block — Python will run the code inside it, but if an error occurs, it will jump to the matching except block.

---

2️⃣ d = {"a": 1}

• Creates a dictionary d with one key-value pair:

  • Key: "a"

  • Value: 1

So d looks like:

{"a": 1}

---

3️⃣ print(d["b"])

• This tries to access the value for the key "b".

• Since "b" is not present in the dictionary, Python raises a KeyError.

---

4️⃣ except KeyError:

• This block catches errors of type KeyError.

• Because the error matches, Python runs the code inside this block instead of stopping the program.

---

5️⃣ print("Key missing")

• Prints the message "Key missing" to tell the user that the requested key doesn’t exist.

---

✅ Final Output:

Key missing

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Python Coding Challange - Question with Answer (01100825)

 

Let’s break your code down step-by-step so it’s crystal clear.

---

count = 1             # Step 1: Start with count set to 1
while count <= 3: # Step 2: Keep looping as long as count is 3 or less
    print(count * 2) # Step 3: Multiply count by 2 and print the result 
    count += 1 # Step 4: Increase count by 1 (count = count + 1)

How it runs:

1. First loop

   count = 1

   • count <= 3 → True

   • Print 1 * 2 = 2

   • Increase count → now count = 2

2. Second loop

   count = 2

   • count <= 3 → True

   • Print 2 * 2 = 4

   • Increase count → now count = 3

3. Third loop

   count = 3

   • count <= 3 → True

   • Print 3 * 2 = 6

   • Increase count → now count = 4

4. Fourth check

   count = 4

   • count <= 3 → False → loop stops.

---

Final output:

2
4
6

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Python Coding challenge - Day 663| What is the output of the following Python Code?

 

1. Importing the NumPy library

import numpy as np

Imports the NumPy library as np for numerical computations and array manipulations.

2. Creating a NumPy array arr

arr = np.array([10, 20, 30, 40])

Creates a NumPy array named arr with elements [10, 20, 30, 40].

3. Creating a boolean mask to select elements greater than 15

mask = arr > 15

Compares each element of arr to 15 and creates a boolean array mask:

For 10 → False

For 20 → True

For 30 → True

For 40 → True

So, mask = [False, True, True, True].

4. Assigning the value 5 to elements of arr where mask is True

arr[mask] = 5

Uses boolean indexing to update elements of arr where mask is True.

Elements at indices 1, 2, and 3 (values 20, 30, 40) are replaced with 5.

Updated arr becomes [10, 5, 5, 5].

5. Calculating and printing the sum of updated arr

print(np.sum(arr))

Calculates the sum of the updated array arr:

10 + 5 + 5 + 5 = 25

Prints 25.

Final output:

25

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Python Coding challenge - Day 662| What is the output of the following Python Code?

Code Explanation:

1. Importing the NumPy library

import numpy as np

Imports the NumPy library as np for numerical operations and array handling.

2. Creating a NumPy array arr

arr = np.array([1, 2, 3, 4, 5])

Creates a NumPy array named arr with elements [1, 2, 3, 4, 5].

3. Creating a list of indices idx

idx = [0, 2, 4]

Creates a Python list idx containing indices [0, 2, 4].

These indices correspond to elements in arr at positions 0, 2, and 4.

4. Indexing arr with idx to create new_arr

new_arr = arr[idx]

Uses fancy indexing to select elements from arr at indices 0, 2, and 4.

new_arr contains [1, 3, 5].

Note: This creates a new array, a copy, not a view.

5. Modifying an element of new_arr

new_arr[1] = 99

Sets the element at index 1 of new_arr (which is currently 3) to 99.

Now, new_arr becomes [1, 99, 5].

Since new_arr is a copy, this does not modify the original arr.

6. Calculating and printing the sum of arr and new_arr

print(np.sum(arr) + np.sum(new_arr))

Calculates the sum of the original array arr: 1 + 2 + 3 + 4 + 5 = 15

Calculates the sum of the modified new_arr: 1 + 99 + 5 = 105

Adds the sums: 15 + 105 = 120

Prints 120.

Final output:

120

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Python Coding challenge - Day 661| What is the output of the following Python Code?

 

Code Explanation:

1. Importing pandas and NumPy libraries

import pandas as pd

import numpy as np

Imports the pandas library as pd for data manipulation.

Imports NumPy as np for numerical operations, including handling NaN values.

2. Creating a DataFrame df with missing values

df = pd.DataFrame({'A': [1, np.nan, 3, np.nan, 5]})

Creates a DataFrame df with a single column 'A'.

The values are [1, NaN, 3, NaN, 5], where np.nan represents missing data.

3. Filling missing values with 0

df['A'] = df['A'].fillna(0)

Replaces all NaN values in column 'A' with 0.

After this operation, column 'A' becomes [1, 0, 3, 0, 5].

4. Calculating and printing the sum of column 'A'

print(df['A'].sum())

Calculates the sum of the updated column 'A'.

Sum = 1 + 0 + 3 + 0 + 5 = 9.

Prints 9.

Output:

9

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Python Coding challenge - Day 642| What is the output of the following Python Code?

 

Code Explanation:

1. Defining the Outer Function

def outer():

    count = [0]

This is a function named outer.

Inside it, a list count = [0] is defined.

We use a list instead of an integer because lists are mutable and allow nested functions (closures) to modify their contents.

2. Defining the Inner Function

    def inner():

        count[0] += 1

        return count[0]

inner() is defined inside outer(), so it forms a closure and can access the count list from the outer scope.

count[0] += 1: This increases the first (and only) element of the list by 1.

It then returns the updated value.

3. Returning the Inner Function (Closure)

    return inner

The outer() function returns the inner() function — not executed, just the function itself.

This returned function will remember the count list it had access to when outer() was called.

4. Creating Two Independent Closures

f1 = outer()

f2 = outer()

f1 is assigned the result of outer() — which is the inner function with its own count = [0].

f2 is another independent call to outer(), so it also gets its own count = [0].

Each closure (f1 and f2) maintains its own separate state.

5. Printing the Results of Function Calls

print(f1(), f1(), f2(), f1(), f2())

Let’s evaluate each call:

f1() → increases f1’s count[0] from 0 to 1 → returns 1

f1() → count[0] becomes 2 → returns 2

f2() → its own count[0] becomes 1 → returns 1

f1() → count[0] becomes 3 → returns 3

f2() → count[0] becomes 2 → returns 2

Final Output:

1 2 1 3 2

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Python Coding challenge - Day 656| What is the output of the following Python Code?

 

Code Explanation:

1. Importing partial from functools

from functools import partial

This line imports the partial function from Python’s functools module.

partial allows you to fix some portion of a function’s arguments and generate a new function with fewer arguments.

2. Defining the function add

def add(x, y):

    return x + y

Defines a function named add that takes two parameters: x and y.

The function returns the sum of x and y.

3. Creating a new function add_five using partial

add_five = partial(add, y=5)

Uses partial to create a new function called add_five.

This new function has the argument y fixed to 5.

Essentially, add_five is equivalent to add(x, 5).

When you call add_five, you only need to provide the remaining argument x.

4. Calling add_five with an argument and printing the result

print(add_five(10))

Calls the new function add_five with x = 10.

Since y is already fixed to 5 by partial, this computes add(10, 5), which returns 15.

The result 15 is printed to the console.

Final Output:

15

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Python Coding Challange - Question with Answer (01090825)

 

Let’s go through it step-by-step:

---

def square_last(nums):
    nums[-1] **= 2

• def square_last(nums): → Defines a function named square_last that takes a parameter nums (expected to be a list).

• nums[-1] → Accesses the last element in the list. In Python, -1 is the index for the last item.

• **= → This is the exponentiation assignment operator. x **= 2 means "square x" (raise it to the power of 2) and store it back in the same position.

---

a = [2, 4, 6]

• Creates a list named a with three elements: 2, 4, and 6.

---

square_last(a)

• Calls the function square_last, passing a as nums.

• Inside the function, nums[-1] is 6.

• 6 **= 2 → 6 squared = 36.

• This updates the last element of the list to 36.

---

print(a)

• Since lists are mutable in Python, the change inside the function affects the original list.

• Output will be:

[2, 4, 36]

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Python Coding challenge - Day 660| What is the output of the following Python Code?

 

Code Explanation:

1. Importing the pandas library

import pandas as pd

Imports the pandas library with the alias pd, which is used for data manipulation and analysis.

2. Creating a DataFrame df

df = pd.DataFrame({'A': [1, 2, 3, 4], 

                   'B': [5, 6, 7, 8]})

Creates a pandas DataFrame named df with two columns:

'A' contains [1, 2, 3, 4]

'B' contains [5, 6, 7, 8]

3. Creating a filtered slice of df

df_slice = df[df['A'] > 2]

Creates a new DataFrame df_slice by selecting rows where the value in column 'A' is greater than 2.

df_slice will have rows where 'A' is 3 and 4, so:

   A  B

2  3  7

3  4  8

4. Modifying column 'B' in df_slice

df_slice['B'] = 0

Attempts to set the values in column 'B' of df_slice to 0 for all rows in the slice.

Important: This creates a SettingWithCopyWarning because df_slice is a filtered view or copy of df.

Modifying df_slice does not modify the original df unless explicitly done using .loc.

5. Printing the sum of column 'B' in the original DataFrame df

print(df['B'].sum())

Calculates the sum of column 'B' in the original DataFrame df.

Since df was not modified by changing df_slice, column 'B' remains [5, 6, 7, 8].

Sum = 5 + 6 + 7 + 8 = 26

Final output:

26

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Python Coding challenge - Day 659| What is the output of the following Python Code?

 

Code Explanation:

1. Importing NumPy library

import numpy as np

Imports the NumPy library with the alias np, which provides support for arrays and mathematical operations.

2. Creating a NumPy array p

p = np.array([10, 20, 30])

Creates a NumPy array named p with elements [10, 20, 30].

3. Creating a copy of p and assigning it to q

q = p.copy()

Creates a new, independent copy of the array p.

q contains [10, 20, 30] but is stored separately in memory (no shared data with p).

4. Assigning r to reference the same array as q

r = q

Assigns r to reference the same object as q.

Both r and q point to the same array in memory.

5. Modifying the element at index 1 of r

r[1] = 99

Updates the value at index 1 in the array referenced by r to 99.

Because r and q share the same array, this change also affects q.

Now both q and r are [10, 99, 30].

p remains unchanged as [10, 20, 30].

6. Calculating and printing the total sum

print(np.sum(p) + np.sum(q) + np.sum(r))

Computes the sums of each array and adds them:

Sum of p = 10 + 20 + 30 = 60

Sum of q = 10 + 99 + 30 = 139

Sum of r = same as q = 139

Total sum = 60 + 139 + 139 = 338

Prints 338 to the console.

Output:

338

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Python Coding challenge - Day 657| What is the output of the following Python Code?

 

Code Explanation:

1. Creating a NumPy array x

x = np.array([4, 5, 6])

Creates a NumPy array x with elements [4, 5, 6].

2. Assigning y to x

y = x

Assigns y to reference the same array object as x.

So, y and x point to the same data in memory.

3. Modifying an element of y

y[2] = 10

Changes the value at index 2 of y to 10.

Since x and y share the same data, this change also affects x.

Now both x and y are [4, 5, 10].

4. Creating a copy z of x

z = x.copy()

Creates a new independent copy of x and assigns it to z.

z now holds [4, 5, 10] initially but is a different object in memory.

5. Modifying an element of z

z[0] = 7

Changes the first element of z to 7.

Now, z is [7, 5, 10].

This does not affect x or y.

6. Calculating and printing the sum

print(np.sum(x) + np.sum(y) + np.sum(z))

Sum of x = 4 + 5 + 10 = 19

Sum of y = same as x = 19

Sum of z = 7 + 5 + 10 = 22

Total = 19 + 19 + 22 = 60

Output:

60

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Python Coding Challange - Question with Answer (01080825)

 

✅ Explanation

In Python, any non-zero number (whether positive or negative) is considered truthy, meaning it evaluates to True in a conditional (if) statement.

So let's break it down:

• a = -1 → a is assigned the value -1

• if a: → Since -1 is not zero, it's treated as True

• Therefore, the code inside the if block runs:

  print("True")

---

 Output:

True

---

🔍 Summary of Truthy & Falsy in Python:

Value	Boolean Meaning
0, 0.0	False
None	False
"" (empty)	False
[], {}, set()	False
400 Days Python Coding Challenges with Explanation	True

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Python Coding challenge - Day 658| What is the output of the following Python Code?

Code Explanation:

1. Importing the NumPy library

import numpy as np

This line imports the NumPy library, giving it the alias np, which is a standard practice.

NumPy provides powerful support for numerical operations and handling arrays efficiently.

2. Creating a NumPy array

arr = np.array([3, 15, 8, 22, 7])

This creates a NumPy array named arr with the elements [3, 15, 8, 22, 7].

The array holds 5 integers.

3. Creating a boolean mask

mask = arr < 10

This line creates a boolean mask based on the condition arr < 10.

It checks each element in arr and returns True if the element is less than 10, otherwise False.

The result of this comparison is:

[True, False, True, False, True]

4. Using the mask to modify the array

arr[mask] = 0

This line uses the mask to update the array arr.

Wherever the mask is True, the corresponding element in arr is replaced with 0.

The elements at indices 0, 2, and 4 are replaced (i.e., 3, 8, and 7).

Updated arr becomes:

[0, 15, 0, 22, 0]

5. Calculating and printing the sum of the array

print(np.sum(arr))

np.sum(arr) computes the sum of all elements in the updated array:

0 + 15 + 0 + 22 + 0 = 37

The result 37 is printed to the console.

Final Output:

37

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Python Coding Challange - Question with Answer (01070825)

 

✅ Explanation:

🔁 for i in range(5)

This loop runs for values of i from 0 to 4 (i.e., 0, 1, 2, 3, 4).

if i % 2 == 0:

This checks if the number is even.

• % is the modulo operator (returns the remainder).

• i % 2 == 0 means the number is divisible by 2 (i.e., even).

⏩ continue

If the number is even, continue tells the loop to skip the rest of the code in the loop body and move to the next iteration.

print(i)

This line only runs if i is odd, because even values were skipped by the continue.

---

Loop Trace:

i	i % 2 == 0	Action
0	True	Skip (continue)
1	False	Print 1
2	True	Skip (continue)
3	False	Print 3
4	True	Skip (continue)

✅ Output:

1
3

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Python Coding challenge - Day 655| What is the output of the following Python Code?

 

 Code Explanation:

1. Importing the partial Function

from functools import partial

This line imports the partial function from Python’s functools module.

partial() lets you pre-fill (or freeze) some arguments of a function to create a new simplified function.

2. Defining the Original Function

def multiply(a, b, c):

    return a * b * c

This defines a function multiply() which takes three arguments: a, b, and c.

It returns the product of the three numbers: a × b × c.

3. Creating a Partially Applied Function

double_and_triple = partial(multiply, a=2, b=3)

This creates a new function called double_and_triple using partial.

The original function multiply() is partially filled with:

a = 2

b = 3

So now, double_and_triple() only needs one argument: c.

Internally, it works like:

multiply(2, 3, c)

4. Calling the Partial Function

print(double_and_triple(4))

You call double_and_triple(4) → this sets c = 4.

So, the full function becomes:

multiply(2, 3, 4)

The result is:

2 × 3 × 4 = 24

5. Final Output

24

The final printed output is 24.

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Python Coding challenge - Day 654| What is the output of the following Python Code?

 

Code Explanation:

1. Importing partial

from functools import partial

You import the partial function from Python's functools module. This function allows you to fix a few arguments of a function and generate a new function with fewer parameters.

2. Defining the Original Function

def add(x, y, z):

    return x + y + z

A function add is defined which takes three arguments (x, y, and z) and returns their sum.

3. Creating a Partially Applied Function

add_to_five = partial(add, x=2, y=3)

Using partial, a new function add_to_five is created from add by fixing:

x = 2

y = 3

Now add_to_five only requires the third argument z when called.

4. Calling the Partial Function

print(add_to_five(4))

You call add_to_five(4), which supplies z = 4.

Internally, this calls:

add(2, 3, 4)

Which returns:

2 + 3 + 4 = 9

5. Final Output

9

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HarvardX: Introduction to Data Science with Python

 

HarvardX: Introduction to Data Science with Python

Overview of the Course

HarvardX: Introduction to Data Science with Python is a beginner-friendly yet in-depth online course that provides a solid foundation in the key concepts, tools, and practices of modern data science using the Python programming language. Offered through edX by Harvard University, this course is part of the HarvardX Data Science Professional Certificate, which has become one of the most respected and recognized data science learning paths globally.

The course is designed to teach you how to collect, analyze, and interpret data in meaningful ways. By blending programming, statistics, and real-world applications, this course prepares learners to use data science for decision-making, research, and problem-solving in a wide variety of domains.

What You’ll Learn

This course introduces students to essential topics in data science, including:

Python programming basics and libraries such as pandas, numpy, and matplotlib

Data wrangling and preprocessing techniques

Data visualization to understand and communicate insights

Probability and statistical inference

Hypothesis testing

Exploratory Data Analysis (EDA)

Introduction to machine learning concepts

Each topic is approached through practical, hands-on projects and problem sets using real datasets, making the learning experience both engaging and applicable.

Tools and Libraries Covered

Students use industry-standard tools and Python libraries throughout the course. These include:

• Python 3: The core programming language used
• Jupyter Notebooks: Interactive coding environment for data science
• Pandas: For data manipulation and analysis
• NumPy: For numerical operations and array handling
• Matplotlib & Seaborn: For data visualization
• SciPy: For statistical computations
• Scikit-learn: (in later modules) For machine learning tasks

No prior experience with Python is required, although some familiarity with programming and statistics is helpful.

Course Structure

The course typically unfolds over 8–10 weeks, with each week focusing on a specific part of the data science pipeline. Here's a rough breakdown of the modules:

• Introduction to Python and Jupyter Notebooks
• Working with DataFrames using Pandas
• Exploring and Visualizing Data
• Probability and Distributions
• Sampling and Central Limit Theorem
• Statistical Testing
• Correlation and Regression
• Capstone Project

Learners complete quizzes, hands-on labs, and a final project that pulls all concepts together.

Who Should Take This Course?

This course is perfect for:

Beginners with a curiosity about data science

Students looking to explore data careers

Professionals transitioning from other fields like business, finance, or healthcare

Researchers and analysts wanting to level up their data skills

The gentle introduction to programming makes it ideal for non-CS majors, and the rigor of statistical analysis ensures that even intermediate learners will find it valuable.

What Makes It Unique?

What sets this course apart is Harvard’s academic rigor paired with a practical, applied approach. It doesn’t just teach you Python or data theory — it helps you think like a data scientist. The inclusion of case studies, real datasets, and the step-by-step problem-solving process makes the learning stick.

Additionally, you’ll benefit from:

Lectures by expert faculty from Harvard’s Department of Statistics

A supportive community of learners

A certificate (optional, paid) that holds real value in the job market

Real-World Applications

By the end of this course, you’ll be capable of:

Cleaning and preparing messy datasets

Performing statistical analysis to answer real questions

Creating clear and compelling visualizations

Building simple models to make predictions

Communicating insights to non-technical audiences

These are precisely the tasks you'll face as a data analyst, data scientist, or even researcher in any field.

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Final Thoughts

If you’re looking to start a career in data science or just want to gain a solid understanding of how data can be used to make decisions, HarvardX’s Introduction to Data Science with Python is an excellent place to begin. Backed by Harvard's academic excellence and focused on hands-on, applied learning, it offers a perfect balance of theory and practice. Whether you’re analyzing stock trends, studying disease outbreaks, or just visualizing sales data — this course will give you the tools and confidence to do it right.

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HarvardX: CS50's Mobile App Development with React Native

 

HarvardX: CS50's Mobile App Development with React Native

What Is This Course About?

CS50’s Mobile App Development with React Native is a comprehensive course offered by Harvard University through edX. It is a continuation of the world-renowned CS50 Introduction to Computer Science and focuses specifically on building mobile apps for both iOS and Android using React Native, a powerful cross-platform JavaScript framework.

The course is designed to teach not only how to build functional and beautiful user interfaces but also how to integrate device features like the camera, location, and notifications into your apps. With its mix of theory, hands-on practice, and project-based learning, it’s an excellent resource for developers looking to break into mobile development.

Why React Native?

React Native allows developers to use JavaScript and React to build native mobile applications. Unlike traditional native development (using Swift for iOS or Kotlin for Android), React Native lets you write a single codebase that runs on both platforms. This means faster development cycles, easier maintenance, and better scalability.

Moreover, tools like Expo make it even easier to test and deploy apps without needing an Apple device or developer license during the development phase.

Course Structure

The course is divided into weekly modules, each focusing on a specific part of mobile development. Topics include:

Week 1–2: Introduction to React Native and JSX

Week 3–4: Component structure and navigation

Week 5–6: State management and Context API

Week 7–8: Fetching data from APIs

Week 9–10: Local storage using AsyncStorage

Week 11–12: Using native device features

Week 13: Final project (you build and publish your own app)

Each week includes lectures, code walkthroughs, and assignments to help solidify your understanding.

What Will You Learn?

By the end of this course, you will be able to:

Build beautiful, responsive mobile UIs using React Native components

Implement multi-screen navigation with React Navigation

Connect to and consume data from public APIs

Store and retrieve data locally using AsyncStorage

Use device features like GPS, camera, microphone, and notifications

Deploy your apps to Google Play Store or Apple App Store using Expo

You’ll also learn good practices in code organization, asynchronous programming, and UI/UX principles tailored for mobile apps.

Tools & Technologies Used

The course uses modern tools in mobile development, including:

React Native – for building cross-platform apps

Expo CLI – for easier development, testing, and deployment

React Navigation – for screen management

JavaScript (ES6+) – as the main programming language

VS Code – recommended IDE

Git/GitHub – for version control

No need for Xcode or Android Studio unless you're publishing to app stores. Most of your development and testing can be done directly on your phone via Expo Go.

Who Is This Course For?

This course is ideal for:

Students who completed CS50 and want to go deeper

Web developers transitioning to mobile development

Startup founders and freelancers who want to build MVPs

Anyone looking to enter the mobile development job market

You should have some experience with JavaScript, React, and basic CS concepts before starting.

Join Free:HarvardX: CS50's Mobile App Development with React Native

Final Thoughts

CS50’s Mobile App Development with React Native is more than just a technical course — it’s a launchpad for your mobile development career. You’ll learn how to turn ideas into fully functional apps, gain hands-on experience with in-demand tools, and build a project you can be proud of.

Whether you’re building your first app or aiming to freelance or land a mobile dev job, this course is an excellent investment of your time — especially since it’s free to start.

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Python Coding challenge - Day 652| What is the output of the following Python Code?

 

Code Explanation:

1. Function Definition

def make_adder(x):

    return lambda y: lambda z: x + y + z

Explanation:

This defines a function called make_adder that takes one argument x.

Inside the function, it returns a lambda function, which itself returns another lambda function.

So, it's a function that returns a function that returns a function.

Structure:

make_adder(x)

    └── lambda y:

           └── lambda z: x + y + z

Each time you call a lambda, it returns another function until all arguments x, y, and z are supplied.

2. First Function Call

f = make_adder(2)

Explanation:

You're calling make_adder(2), so now x = 2.

This returns a new function: lambda y: lambda z: 2 + y + z

The variable f now holds this function:

f = lambda y: lambda z: 2 + y + z

3. Second Function Call

g = f(3)

Explanation:

Now f is lambda y: lambda z: 2 + y + z

You're calling f(3), so y = 3

This evaluates to:

g = lambda z: 2 + 3 + z

So g is now a function that takes one argument z and returns 2 + 3 + z (which is 5 + z).

4. Final Function Call

print(g(4))

Explanation:

Now g = lambda z: 5 + z

Calling g(4) means z = 4, so:

g(4) = 5 + 4 = 9

So the output is:

9

Final Output

9

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Python Coding challenge - Day 653| What is the output of the following Python Code?

 

Code Explanation:

1. Importing partial from functools

from functools import partial

Explanation:

This line imports the partial function from the functools module.

partial is used to "freeze" some portion of a function’s arguments and/or keywords — resulting in a new function with fewer parameters.

2. Defining the subtract Function

def subtract(a, b):

    return a - b

Explanation:

A function subtract is defined, which takes two arguments: a and b.

It returns the result of a - b.

Examples:

subtract(10, 3) returns 7

subtract(3, 10) returns -7

3. Creating a Partial Function

minus_five = partial(subtract, b=5)

Explanation:

partial(subtract, b=5) creates a new function where the value of b is fixed at 5.

The result is a new function that only needs the a argument.

minus_five(a) will now return a - 5.

It's equivalent to:

def minus_five(a):

    return subtract(a, 5)

4. Calling the Partial Function

print(minus_five(12))

Explanation:

You're calling minus_five(12) → internally this does subtract(12, 5)

Result: 12 - 5 = 7

So the output is:

7

Final Output

7

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Python Coding Challange - Question with Answer (01060825)

 

Let's break down the code step by step:

def clear_list(lst):
    lst.clear()

• A function named clear_list is defined.

• It takes a parameter lst, which is expected to be a list.

• Inside the function, lst.clear() is called.

  • The .clear() method empties the original list in place — it removes all elements from the list but does not create a new list.

---

values = [10, 20, 30]

• A list named values is created with three integers: [10, 20, 30].

---

clear_list(values)

• The clear_list function is called with values as the argument.

• Inside the function, the list is modified in place, so values becomes [] (an empty list).

---

print(values)

• Since the original list values was cleared inside the function, this prints:

[]

---

✅ Final Output:

[]

💡 Key Concept:

• Methods like .clear(), .append(), .pop(), etc., modify the list in place.

• Because lists are mutable objects in Python, passing a list into a function allows the function to modify the original list, unless the list is reassigned.

400 Days Python Coding Challenges with Explanation

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Python Coding Challange - Question with Answer (01050825)

 

Let's break down this code line by line:

a = [5, 6, 7]

• A list a is created with three elements: [5, 6, 7].

---

b = a[:]

• This creates a shallow copy of list a and assigns it to b.

• The [:] slicing notation means: copy all elements of a.

• Now, a and b are two separate lists with the same values:

  a = [5, 6, 7] 
  b = [5, 6, 7]

---

b.remove(6)

• This removes the value 6 from list b.

• Now b = [5, 7], but a is still [5, 6, 7] because it was not changed.

---

print(a)

• This prints the original list a, which is still:

[5, 6, 7]

---

🔍 Summary:

• a[:] creates a new independent copy.

• Modifying b does not affect a.

• Output:

[5, 6, 7]

Python for Software Testing: Tools, Techniques, and Automation

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Python Coding challenge - Day 650| What is the output of the following Python Code?

 

Code Explanation:

1. Importing partial from functools

from functools import partial

This imports the partial function.

partial is used to pre-fill some arguments of a function, creating a new version with fewer parameters.

2. Defining a Function multiply(x, y)

def multiply(x, y):

    return x * y

This is a simple function that takes two arguments x and y, and returns their product (x * y).

3. Creating a New Function with partial

double = partial(multiply, y=2)

Here, partial creates a new function called double.

It uses multiply but pre-fills the argument y=2.

So double(n) is now equivalent to multiply(n, 2) → i.e., it doubles the number.

4. Calling the double Function

print(double(5))

This calls double(5), which internally does multiply(5, 2) → result is 10.

The result 10 is printed.

Final Output

10

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Python Coding challenge - Day 651| What is the output of the following Python Code?

 

Code Explanation:

1. Importing partial from functools

from functools import partial

You are importing the partial function from Python’s built-in functools module.

partial lets you fix some arguments of a function and create a new function with fewer parameters.

2. Defining the divide Function

def divide(a, b):

    return a / b

This function takes two parameters:

a: the numerator

b: the denominator

It returns the result of dividing a by b.

3. Creating a New Function half Using partial

half = partial(divide, b=2)

You are creating a new function called half using partial.

It uses the divide function and pre-fills b = 2.

Now, calling half(x) is the same as calling divide(x, 2) — i.e., it divides the input by 2.

4. Calling half with Argument 10

print(half(10))

This is equivalent to:

divide(10, 2) → 10 / 2 → 5.0

So, it prints the result: 5.0

Final Output

5.0

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