Function c computes factorial recursively. Function a repeatedly removes the last decimal digit until only the leading digit remains. Thus c(8)=40320 and a(c(8))=4, as required. These functions must be composed in that order: factorial first, leading digit second.
**Answer: B.**
A: **Incorrect:** Returns 8 directly, not 4.
B: **Correct:** Computes the leading digit of 8!=40320, giving 4.
C: **Incorrect:** a(8)=8, so applying a again still gives 8.
D: **Incorrect:** 8//10 is zero, not 4.
The first item pen has no earlier items, so its inner loop is empty and it is not appended. Each later item has length 6, which differs from the earlier pen's length 3. Therefore each is appended as soon as the comparison with pen succeeds, and the inner break prevents duplicate appends. The output is ['pencil','eraser','marker'].
**Answer: A.**
A: **Correct:** Each item after pen finds pen as an earlier different-length item.
B: **Incorrect:** Pencil also differs in length from pen and must be included.
C: **Incorrect:** Eraser also differs in length from pen and must be included.
D: **Incorrect:** Pen has no earlier index to satisfy the inner condition.
The function counts character frequencies, then scans characters alphabetically. It replaces the current winner only for a strictly larger count, so ties favour the alphabetically earliest character. In D, 'bbbcaac', b occurs 3 times and a and c occur twice, so b wins. In A, a and b tie at 3, so a wins; in B and C, a,b,c all tie at 2, so a wins.
**Answer: D.**
A: **Incorrect:** a and b tie at three occurrences; sorted iteration keeps a.
B: **Incorrect:** All three letters tie at two; sorted iteration keeps a.
C: **Incorrect:** All three letters tie at two; sorted iteration keeps a.
D: **Correct:** b is uniquely most frequent, with three occurrences.
selector(25) selects numbers for which (x-1)%4==0: [1,5,9,13,17,21,25]. All are odd, so aggregator retains and sums all seven. Their arithmetic-progression sum is 7×(1+25)/2=91. controller returns this sum, which is then printed.
**Answer: C.**
A: **Incorrect:** Does not equal the sum of the selected progression.
B: **Incorrect:** Does not follow the x≡1 modulo 4 selection rule.
C: **Correct:** 91 is the sum of all seven selected odd numbers.
D: **Incorrect:** Omits terms of the selected progression.
Code 1 changes a list stored inside a tuple, which is permitted because the tuple's reference is not replaced. Code 2 concatenates a tuple and rebinds Y to a new tuple; this is also permitted. Code 3 assigns to Z[1], directly trying to replace a tuple element, so it raises TypeError. Tuple immutability concerns its slots, not the mutability of referenced objects.
**Answer: C.**
A: **Incorrect:** Appending to a contained list is legal.
B: **Incorrect:** Tuple += creates a new tuple and rebinds the name; it is legal.
C: **Correct:** Only the assignment to a tuple slot is forbidden.
D: **Incorrect:** Code 3 does raise TypeError.
The dictionary counts characters in 'machinelearningwithpython'. n appears three times, while i, a, e, h, r and t each appear twice and the other letters once. The maximum-frequency scan therefore selects n. Sorting keys only controls the winner in a frequency tie; it does not change the counts.
**Answer: B.**
A: **Incorrect:** i occurs twice, less often than n.
B: **Correct:** n occurs three times and has the unique maximum.
C: **Incorrect:** e occurs twice.
D: **Incorrect:** a occurs twice.
The finally block executes only when an exception occurs
Published solution
For f(2), try prints T and computes a pending return value 5. Before returning, finally prints Y and returns F, overriding that value. For f(0), try prints T, division raises ZeroDivisionError, except prints E and prepares Z; finally again prints Y and overrides the return with F. The full printed sequence is T,Y,T,E,Y on separate lines, and both p and q are 'F'. A finally block runs on normal return as well as handled exceptions.
**Answer: B, E, F.**
A: **Incorrect:** This is only the second call's three-line sequence; it omits the first call's T,Y output, so it is not the complete output intended by the option.
B: **Correct:** Gives the complete five-line printed sequence.
C: **Incorrect:** The return from finally overrides the pending 5.
D: **Incorrect:** The return from finally overrides the pending Z.
E: **Correct:** The first call ultimately returns F.
F: **Correct:** The second call also ultimately returns F.
G: **Incorrect:** The first call has no exception and still executes finally.
Sort records using score (tuple index 1) descending, retain only scores>80, and return the names at index 0. A combines these steps in a comprehension. B expresses the same operations with sorted, filter and map. Filtering a sorted sequence preserves its score order.
**Answer: A, B.**
A: **Correct:** Uses the score sorting key, strict filter and name projection.
B: **Correct:** Sorts by descending score, filters strictly above 80 and maps tuples to names.
C: **Incorrect:** Default sorting orders tuples primarily by name and retains tuples, not the required name list.
D: **Incorrect:** Includes score 80 and does not perform the required descending sort.
Select **all** that apply.
**Note**
• If a value is passed to
, it reads that many number of characters from the current
position of the file pointer.
• The
method moves the position of the file pointer to the given number of chars after the
start of the file.
6406536932488.
The first line of the output is
.
6406536932489.
The second line of the output is
.
6406536932490.
The second line of the output is
.
6406536932491.
There are 5 lines in the output.
6406536932492.
The output contains empty lines.
Published solution
The file contains Line1 through Line10 joined by newline characters. Two readline calls skip Line1 and Line2. read(5) returns 'Line3', leaving its newline unread. The next readline consumes that newline; read(10) then returns 'Line4\nLine', which prints across two lines. seek(0) resets the pointer; read(5) returns 'Line1'. A readline consumes its newline and another skips Line2, so the last read(5) returns 'Line3'. The displayed lines are Line3, Line4, Line, Line1, Line3: five lines with no blank line.
**Answer: A, C, D.**
A: **Correct:** The first two readline calls position the first print at Line3.
B: **Incorrect:** The second printed line is Line4, not Line5.
C: **Correct:** The next read starts at Line4 after consuming Line3's newline.
D: **Correct:** One print contains an embedded newline, giving five output lines from four print calls.
E: **Incorrect:** The embedded newline separates nonempty text; no output line is empty.
Each recursive call counts uppercase letters at the two ends, then recurses on the interior slice lst[1:-1]. The pairs are A/G (2), b/f (0), C/E (2), and central d (0). Total=2+0+2+0=4. The single-element base case counts the central element only once.
**Answer: 4.**
Start total=1,err=0. The successful try operations multiply rather than add: for 5, total becomes 1×(10//5)=2; for '2', it becomes 2×(10//2)=10. Zero raises ZeroDivisionError, so err gains 3 and total gains 2, becoming 12. 'x' fails int conversion and the general except adds 1 to err. Final total=12 and err=4, so the print is 16. Failed right-hand expressions do not perform the multiplication assignment.
**Answer: 16.**
Fill in the blank with the missing expression so that the following conditions hold:
Published solution
Use a positive integer divisor 4 in the missing slot. The base cases give f(0)=0 and f(1)=1. Then f(2)=f(1)+f(0)=1, f(3)=f(1)+f(0)=1, and f(4)=f(2)+f(1)=2, satisfying all three requirements. A divisor larger than 4 would make f(4)=f(2)+f(0)=1; divisors 2 or 3 fail an earlier required value.
**Answer: 4.**
S accumulates copies of successive prefixes rather than being reset. At i=0, S=[2], contributing 2 to T. At i=1, S becomes [2,2,4], contributing 8. At i=2, S becomes [2,2,4,2,4,6], contributing 20. Therefore the final running total is 2+8+20=30. The inner loop traverses the entire accumulated S after each extension.
**Answer: 30.**
What is the output?
Note : The function divmod(a, b) gives two values:
(quotient : x // 10 , remainder : x % 10)
for example: divmod(27, 10) gives (2, 7)
Published solution
reduce_once repeatedly uses divmod(x,10) to remove the last digit and add that remainder, producing the digit sum. For 999 the first sum is 9+9+9=27. Since 27 still has two digits, g recurses and sums them to 2+7=9. The one-digit base case then returns 9. The recursion repeats digit summation until a single digit remains.
**Answer: 9.**
Based on the above data, answer the given subquestions.
What is printed by
?
6406536932498.
4
6406536932499.
No output
6406536932500.
7
6406536932501.
8
Published solution
Trace the moves UUDUDDDUU. Starting from floor 0, the successive floors are 1,2,1,2,1,0,-1,0,1. None equals -2, so the conditional print(i+1) is never executed and break is never reached. The later print(u,d) still runs; 'No output' here refers specifically to the conditional print asked about.
**Answer: B.**
A: **Incorrect:** The fourth move leaves floor 2, not -2.
B: **Correct:** The floor never reaches -2, so this print produces no output.
C: **Incorrect:** The seventh move reaches -1, not -2.
D: **Incorrect:** The eighth move returns to zero, not -2.
The floor never reaches -2, so all nine moves are processed. There are five U characters and four D characters. The loop increments u or d for each corresponding move, and the final print(u,d) therefore outputs `5 4`.
**Answer: C.**
A: **Incorrect:** There are five upward moves, not four.
B: **Incorrect:** The loop processes all nine moves, not just six.
C: **Correct:** Correctly counts five U moves and four D moves.
D: **Incorrect:** Interchanges the upward and downward counts.
Based on the above data, answer the given subquestions.
What is the value of
?
6406536932506.
1
6406536932507.
2
6406536932508.
3
6406536932509.
8
Published solution
Counter.count is a shared class attribute increased once by each constructor. a=Counter(3) and b=Counter(5) create two instances, so the class count becomes 2. Calls to inc change each instance's x, not the class count.
**Answer: B.**
A: **Incorrect:** There are two constructor calls, not one.
B: **Correct:** The class counter is incremented exactly twice.
C: **Incorrect:** inc does not construct a third object.
D: **Incorrect:** 8 is the sum of the initial x values, unrelated to the object counter.
Based on the above data, answer the given subquestions.
What is the value of
?
6406536932510.
8
6406536932511.
10
6406536932512.
11
6406536932513.
12
Published solution
a starts with x=3 and a.inc() increases it to 4, returning c=4. b starts with x=5 and b.inc() increases it to 6, returning d=6. The instances have separate x attributes. Therefore c+d=4+6=10.
**Answer: B.**
A: **Incorrect:** Uses the original 3+5 without applying increments.
B: **Correct:** Correctly adds the two returned updated values, 4 and 6.
C: **Incorrect:** Includes an extra increment absent from the code.
D: **Incorrect:** Does not match either instance's single increment.