Python Conditional Statement Exercises

Question

Hi. I have been doing some conditional statement exercises and I need some help with couple of them.

Write a Python program to convert temperatures to and from Celsius and Fahrenheit. [ Formula : c/5 = f-32/9 [ where c = temperature in celsius and f = temperature in fahrenheit ] Expected Output : 60°C is 140 in Fahrenheit 45°F is 7 in Celsius

temp = input("Input the  temperature you like to convert? (e.g., 45F, 102C etc.) : ")
degree = int(temp[:-1])
i_convention = temp[-1]

if i_convention.upper() == "C":
  result = int(round((9 * degree) / 5 + 32))
  o_convention = "Fahrenheit"
elif i_convention.upper() == "F":
  result = int(round((degree - 32) * 5 / 9))
  o_convention = "Celsius"
else:
  print("Input proper convention.")
  quit()
print("The temperature in", o_convention, "is", result, "degrees.")

degree = int(temp[:-1]) i_convention = temp[-1] This part is I don't understand. How can temp be a list when it is a string?

Write a Python program that accepts a word from the user and reverses it.

word = input("Input a word to reverse: ")

for char in range(len(word) - 1, -1, -1):
  print(word[char], end="")
print("\n")

for char in range(len(word) - 1, -1, -1) Start,stop and range. But len means the number of words. It should omit one letter because of that but it does not. How?

Write a Python program that takes two digits m (row) and n (column) as input and generates a two-dimensional array. The element value in the i-th row and j-th column of the array should be i*j. Note : i = 0,1.., m-1 j = 0,1, n-1.

row_num = int(input("Input number of rows: "))
col_num = int(input("Input number of columns: "))
multi_list = [[0 for col in range(col_num)] for row in range(row_num)]

for row in range(row_num):
    for col in range(col_num):
        multi_list[row][col]= row*col

print(multi_list)

multi_list = [[0 for col in range(col_num)] for row in range(row_num)]

I don't understand this variable at all. How does it work?

Write a Python program that accepts a sequence of comma separated 4 digit binary numbers as its input. The program will print the numbers that are divisible by 5 in a comma separated sequence. Sample Data : 0100,0011,1010,1001,1100,1001 Expected Output : 1010

items = []
num = [x for x in input().split(',')]
for p in num:
    x = int(p, 2)
    if not x%5:
        items.append(p)
print(','.join(items))

num = [x for x in input().split(',')] for p in num: x = int(p, 2) if not x%5: items.append(p)

num list is I can't make sense of. Other part is if statement. Question ask me to find digits that can be divided by 5. It says not x%5. How does it work?

Write a Python program to print the alphabet pattern 'D'. Expected Output:(D looks little off becuase I had to type it. Looked weird when I tried to paste it.)

* * * *                                                                  
*        *                                                       
*         *                                                      
*         *                                                      
*         *                                                      
*         *
* * * *

result_str="";    
for row in range(0,7):    
    for column in range(0,7):     
        if (column == 1 or ((row == 0 or row == 6) and (column > 1 and column < 5)) or (column == 5 and row != 0 and row != 6)):  
            result_str=result_str+"*"    
        else:      
            result_str=result_str+" "    
    result_str=result_str+"\n"    
print(result_str);

There is definetly an easy way to do this with a function but I want to understand this part:

for column in range(0,7):
if (column == 1 or ((row == 0 or row == 6) and (column > 1 and column < 5)) or (column == 5 and row != 0 and row != 6)):

Answer 1 · 2023-06-16T03:56:25Z

June 16, 2023 3:56am

Hey there! Some very good questions there.

Celsius > Fahrenheit question

Bracket notation, like [-1] can be used for more than just lists. In this example, it's grabbing the last character of the temp string, which is expected to be F or C

Reverse word question

This comes down to the fact that indexes start at 0. Let's say we use the word "chicken".

len(word) would be 7, and so len(word)-1 would be 6. This range would start at 6
The next -1 is the stopping point. Because range() excludes the given value, so 0 is included in the range

The final -1 is the step, so this returns the range of 6 down to 0 (inclusive) counting backward

So the final range of numbers produced is 6, 5, 4, 3, 2, 1, 0, which targets all 7 letters of "chicken"

Two-dimensional array question

This is a Python List comprehension. There is a new Workshop that is about to be released that goes into depth about this. In the meantime, this Workshop gives an overview of how List Comprehensions work

for col in range(col_num): This is a loop that iterates over the range of values from 0 to col_num - 1. The variable col takes on each value in this range one at a time.
0 for col in range(col_num): This expression assigns the value 0 to each iteration of the col variable. In other words, it creates a list containing col_num number of 0s.
for row in range(row_num): This is another loop that iterates over the range of values from 0 to row_num - 1. The variable row takes on each value in this range one at a time.
[0 for col in range(col_num)]: This list comprehension creates a list of col_num number of 0s. It's essentially the same expression as step 2.
[[0 for col in range(col_num)] for row in range(row_num)]: This is a nested list comprehension where the outer loop iterates over the range of values from 0 to row_num - 1, and for each iteration, the inner loop creates a list of col_num number of 0s. The result is a 2-dimensional list (a list of lists) with row_num rows and col_num columns, where each element is 0.

In summary, the line of code creates a 2D list filled with zeros, with dimensions specified by row_num and col_num.

Binary Numbers Question

This is also a Python List Comprehension. Be sure to refer to the Workshop mentioned above (and watch out for the new one that's coming out soon!).

This line produces a list of values. The input() is split into a list by the , delimiter. Each of these (ie, 0100, 0011, etc) is appended to the new num list

The % operator is the modulo. Read more about the modulo here. x%5 will result in an integer. Positive numbers are treated as True, while 0 is treated as False. Since something that is divisible by 5 will return 0, this conditional will return True if x is divisible by 5, because not 0 (False) evaluates to True

'D' pattern question

for column in range(0, 7): This is a loop that iterates over the range of values from 0 to 6 (inclusive) using the variable column.
if (column == 1 or ((row == 0 or row == 6) and (column > 1 and column < 5)) or (column == 5 and row != 0 and row != 6)): This condition determines whether the code inside the if statement block should be executed. It combines three different conditions using logical operators (or and and):
column == 1: This checks if the value of column is equal to 1.
The first part, (row == 0 or row == 6), checks if the value of row is equal to 0 or 6.
(column == 5 and row != 0 and row != 6): This condition checks if the value of column is equal to 5 and if the value of row is not equal to 0 and not equal to 6.
If any of these conditions evaluate to true, the code inside the if statement block will be executed.
print("*"): This line prints an asterisk character (*). If the conditions in the if statement are true, the code inside the if statement block will be executed, and an asterisk will be printed.

To summarize, this code snippet iterates over the range of values from 0 to 6 using column, and for each value of column, it checks the conditions specified in the if statement. If any of the conditions are true, it prints an asterisk.

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Python Conditional Statement Exercises

1 Answer

Rachel Johnson

Rachel Johnson

Celsius > Fahrenheit question

Reverse word question

Two-dimensional array question

Binary Numbers Question

'D' pattern question

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Rachel Johnson

Rachel Johnson