answer:def is_valid_isbn_10(isbn): # Check if the length is correct if len(isbn) != 10: return False # Initialize the sum sum = 0 # Iterate over the first 9 digits for i in range(9): # Get the digit at the current position digit = int(isbn[i]) if isbn[i].isdigit() else 10 if isbn[i] == 'X' else 0 # Add the product of the digit and its position to the sum sum += digit * (i + 1) # Get the last digit or 'X' last_digit = int(isbn[9]) if isbn[9].isdigit() else 10 # Check if the last digit matches the remainder of sum divided by 11 return last_digit == sum % 11

answer:def double_counts(counts): doubled_counts = [] for count in counts: doubled_counts.append(count * 2) return doubled_counts

answer:Here's the Python function to calculate the slope percentage between two points on a terrain:```pythondef calculate_slope_percentage(point1, point2): x1, y1, z1 = point1 x2, y2, z2 = point2 # Calculate the horizontal distance between the two points horizontal_distance = ((x2 - x1) 2 + (y2 - y1) 2) 0.5 # Calculate the change in elevation elevation_change = z2 - z1 # Calculate the slope percentage if horizontal_distance == 0: return float('inf') # Slope is infinite if points have the same x and y coordinates else: slope_percentage = (elevation_change / horizontal_distance) * 100 return slope_percentage```This function takes two tuples `point1` and `point2` as input, where each tuple represents the coordinates and elevation of a point on the terrain in the format `(x, y, z)`. It then calculates the horizontal distance between the two points using the Pythagorean theorem, and the change in elevation by subtracting the elevations of the two points.If the horizontal distance is zero (i.e., the points have the same x and y coordinates), the function returns `float('inf')` to indicate an infinite slope. Otherwise, it calculates the slope percentage by dividing the change in elevation by the horizontal distance and multiplying by 100.The function returns the slope percentage as a float.

answer:def find_most_frequent_word(text): # Convert the text to lowercase and remove punctuation text = ''.join(char for char in text.lower() if char.isalnum() or char == ' ') # Split the text into words words = text.split() # Create a dictionary to store word frequencies word_freq = {} # Count the frequency of each word for word in words: word_freq[word] = word_freq.get(word, 0) + 1 # Find the most frequent word(s) max_freq = max(word_freq.values()) most_frequent_words = [word for word, freq in word_freq.items() if freq == max_freq] # Return the first most frequent word return most_frequent_words[0]

answer:Here's the Python function to extract dates from a list of radiology report strings:```pythonimport redef extract_dates(reports): date_pattern = r'd{4}-d{2}-d{2}' extracted_dates = [] for report in reports: dates = re.findall(date_pattern, report) extracted_dates.append(dates) return extracted_dates```This function uses the `re` module for regular expression matching to find dates in the format "YYYY-MM-DD" within each report string. Here's how it works:1. The `extract_dates` function takes a list of radiology report strings as input.2. The regular expression pattern `r'd{4}-d{2}-d{2}'` is defined to match dates in the specified format.3. An empty list `extracted_dates` is created to store the extracted dates for each report.4. The function iterates over each report string using a `for` loop.5. For each report, the `re.findall` function is used to find all occurrences of the date pattern in the report string. The resulting list of matched dates is stored in the `dates` variable.6. The `dates` list is appended to the `extracted_dates` list.7. After iterating over all reports, the `extracted_dates` list containing sublists of extracted dates for each report is returned.If a report does not contain any dates in the specified format, the corresponding sublist in the output will be empty.

answer:def calculate_trade_balance(exports, imports): total_exports = sum(exports) total_imports = sum(imports) trade_balance = total_exports - total_imports return trade_balance