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def count_vowels(string): VowelsNumber = 0
for ch in string: if ch.lower() in 'aeiou': VowelsNumber += 1
return VowelsNumber
def main(): StringEntered = input("Enter the string: ") print(f"Number of vowels in your string: {count_vowels(StringEntered)}")
main()
SSolution:olution:
Python Lab 06: Functions
Exercises and solutions
Write the function:
def count_words(string)
that returns the number of words in the given string. Words are sequences of characters
separated by spaces (assume that there is exactly one space between two consecutive
words).
For example, count_words("Mary had a little lamb") should return 5.
Extension : How could the function be modified to correctly handle strings where multiple
spaces appear between words?
06.1.2 Word counting
Write the function:
def count_vowels(string)
that returns the number of vowels in the given string. Vowels are the letters a, e, i, o, u,
including their uppercase versions.
06.1.1 Vowel counting
def count_words(string): counter = 0
for i in range(0, len(string), 1): if (string[i].isspace() and string[i-1].isalpha()) or i == len(string)-1: counter += 1
return counter
SSolution:olution:
EExplanationxplanation The program counts how many vowels are in a string. The count_vowels function goes through each character in the string and, if it is a vowel, it increments a counter. In the main function, the user enters a string and the program prints the number of vowels found.
def main(): StringEntered = input("Enter the string: ") print(f"Your string has {count_words(StringEntered)} words.")
main()
Write the functions:
def sphere_volume(r) def sphere_surface(r) def cylinder_volume(r, h) def cylinder_surface(r, h) def cone_volume(r, h) def cone_surface(r, h)
that compute the volume and surface area of: a sphere with radius r, a circular-based cylinder with radius r and height h, a circular-based cone with radius r and height h.
Then write a program that asks the user for the values of r and h, calls the six functions, and displays the results in the output.
06.1.3 Geometric Solids
def sphere_volume(r): volume = (43.14(r**3))/ return volume
def sphere_surface(r): surface = 43.14(r**2) return surface
def cylinder_volume(r, h): volume = (3.14(r2))h return volume
def cylinder_surface(r, h): surface = 23.14(r2) + 23.14r*h return surface
def cone_volume(r, h): volume = (3.14(r2)h)/ return volume
def cone_surface(r,h): apothem = (r2 + h2)**(1/2)
surface = (3.14r)(apothem + r) return surface
SSolution:olution:
EExplanationxplanation
The count_words function goes through each character and increments the counter whenever it finds a space after a letter or reaches the last character. In the main function, the user enters a string, and the program prints the number of words.
def assign_grant(Income, Children): Grant = 0 if Income > 30000 and Income <= 40000 and Children >= 3: Grant = Children* elif Income > 20000 and Income <= 30000 and Children >= 2: Grant = Children* elif Income <= 20000: Grant = Children*
return Grant
def main(): FamilyIncome = float(input("\nEnter the income: ")) NumberOfChildren = int(input("Enter the number of children in the family: ")) i = 1
while FamilyIncome != -1 and NumberOfChildren != -1:
print(f"Grant Family No. {i}: {assign_grant(FamilyIncome, NumberOfChildren)}") FamilyIncome = float(input("\nEnter the income: ")) NumberOfChildren = int(input("Enter the number of children in the family: ")) i += 1
main()
SSolution:olution:
A non-governmental organization needs a program to calculate the amount of financial aid to
assign to each family in need of assistance. The formula is as follows:
I. If a family’s annual income is between $30,000 and $40,000 and the family has at least 3 children,
the subsidy is $1,000 for each child.
II. If a family’s annual income is between $20,000 and $30,000 and the family has at least 2 children,
the subsidy is $1,500 for each child.
III. If a family’s annual income is less than $20,000, the subsidy is $2,000 for each child.
Write a function that performs these calculations. Then write a program that, in a loop, asks the user
to provide the annual income and the number of children for each family applying for aid, displaying
the corresponding value returned by the function. Use –1 as a sentinel value to terminate data entry.
06.2.1 ONG
EExplanationxplanation
The program calculates financial aid for families based on income and the number of
children. The assign_grant function determines the amount to give according to the given
rules. In the main function, the user enters income and number of children for each family,
and the program prints the corresponding grant until –1 is entered to stop. F-strings are
used here to print datas.
Write a program that converts a Roman numeral, like MCMLXXVIII, into its decimal representation. Hint : first, write a function that returns the numeric value of each single letter, then use the following algorithm:
total = 0 s = string representing the Roman numeral While s is not empty: If s has length 1, or the value of its first character is greater than or equal to the value of its
Add the value of the first character of s to total Remove the first character from s Else: difference = value of the second character of s - value of the first character of s Add difference to total Remove the first two characters from s
06.2.2 Roman numbers
second character
RomanLetters = 'IVXLCDM' CorrispondentValues = [1, 5, 10, 50, 100, 500, 1000]
def ValueRomLett(lett): Position = RomanLetters.find(lett) return CorrispondentValues[Position]
def ConvertToArabicNum(RomanNumber):
Total = 0 s = RomanNumber while len(s) != 0:
if len(s) == 1 or ValueRomLett(s[0]) >= ValueRomLett(s[1]): Total = Total + ValueRomLett(s[0]) s = s[1:]
else: Total = Total + ValueRomLett(s[1]) - ValueRomLett(s[0]) s = s[2:]
return Total
def main():
RomNum = input("Enter the Roman number: ") print(f"The value of the entered Roman number is: {ConvertToArabicNum(RomNum)}")
main()
SSolution:olution:
EExplanationxplanation I define two lists, which are related by their indexes. Then I define a function that returns the value of a Roman letter. Next, I define the main function that converts a Roman numeral into an Arabic number. I keep converting until the Roman numeral is fully processed. If there is only one letter or the value of the first letter is greater than or equal to the second, I add its value and remove the first character. If the value increases, I calculate the difference and add it to the total, then remove the first two characters. Finally, I define main and run it.
An electric wire is a cylindrical conductor covered by an insulating material. The resistance of a
wire is given by the formula:
where ρ is the resistivity of the conductor, and L, A, and d are the length, cross-sectional area,
and diameter of the wire, respectively.
The resistivity of copper is 1.678e-8 Ωm. The wire diameter d is commonly specified by the
American Wire Gauge (AWG), an integer n.
The diameter of an AWG nnn wire is given by:
Write a function
def diameter(wire_gauge)
that takes the wire gauge and returns its diameter.
Write another function
def copper_wire_resistance(length, wire_gauge)
that takes the length and gauge of a copper wire and returns its resistance.
The resistivity of aluminum is 2.82e-8 Ωm.
Write a third function
def aluminum_wire_resistance(length, wire_gauge)
that takes the length and gauge of an aluminum wire and returns its resistance.
Finally, write a program to test these functions.
06.2.4 Electric wire
p_copper = 1.678(10*(-8))
p_aluminum = 2.82(10*(-8))
def diameter(wire_gauge):
d = (0.127(92*((36-wire_gauge)/39)))/
return d
def copper_wire_resistance(length, wire_gauge):
r_copper = (4p_copperlength)/(3.14(diameter(wire_gauge)*2))
return r_copper
def aluminum_wire_resistance(length, wire_gauge):
r_aluminum = (4p_aluminumlength)/(3.14(diameter(wire_gauge)*2))
return r_aluminum
SSolution:olution:
def main(): awg = int(input("1) Enter an AWG value: "))
length_copper = float(input("\n2) Enter the length of the copper wire: ")) awg_copper = float(input("Enter the AWG value of the copper wire: "))
length_aluminum = float(input("\n3) Enter the length of the aluminum wire: ")) awg_aluminum = float(input("Enter the AWG value of the aluminum wire: "))
print(f'\n\n1) Diameter value: {diameter(awg)}') print(f'2) Copper Wire Resistance: {copper_wire_resistance(length_copper, awg_copper)}') print(f'3) Aluminum Wire Resistance: {aluminum_wire_resistance(length_aluminum, awg_aluminum)}')
main()
EExplanationxplanation The program computes the diameter of a wire from its AWG value and uses that diameter to calculate electrical resistance. One function returns the diameter based on the AWG formula, another computes copper resistance, and a third computes aluminum resistance. In the main function, the user enters lengths and gauges, and the program prints the corresponding diameter and resistance values.
Thank you Simone Altaserse
