我的建议是把问题分解成更小的问题，本质上使用一种 * 分治 * 的方法_。通过使单任务函数在出现错误的情况下调试应该更容易。注意getPagebreakList略有不同。

from PyPDF2 import PdfWriter, PdfReader

def page_breaks(pdf_r:PdfReader) -> dict:
    page_breaks = {}
    for i in range(len(pdf_r.pages)):
        pdf_text = pdf_r.pages[i].extract_text() 
        for municipality in array_merged_zone_send:
            pattern = f'PANORAMICA DI {municipality.upper()}'
            if re.search(pattern, pdf_text):
                page_breaks[municipality] = i
    return page_breaks
 

def filenames_range_mapper(pdf_r:PdfReader, page_indices:dict) -> dict:
    num_pages = list(page_indices.values()) + [len(pdf_r.pages)+1] # add last page as well
    # slice the pages from the reader object
    return {name: pdf_r[start:end] for name, start, end in zip(page_indices, num_pages, num_pages[1:])}

def save(file_name:str, pdf_pages:list[PdfReader]) -> None:
    # pass the pages to the writer
    pdf_w = PdfWriter()
    for p in pdf_pages:
        pdf_w.add_page(p)
    
    # write to file
    with open(file_name, "wb") as outputStream:
        pdf_w.write(outputStream) 
    
    # message
    print(f'Pdf "{file_name}" created.')

# main
# ####
# initial location of the file
file_name = "./report1.pdf"
# create reader object
pdf_r = PdfReader(open(file_name, "rb"))
# get index locations of matches
page_breaks = page_breaks(pdf_r)
# dictionary of name-pages slice objects
mapper = filenames_range_mapper(pdf_r, page_breaks)

# template file name
template_output = './zp_{}.pdf'
# iterate over the location-pages mapper
for municipality, pages in ranges.items():
    # set file name
    new_file_name = template_output.format(municipality.title()) # eventually municipality.upper()
    # save the pages into a new file
    save(new_file_name, pages)

使用辅助功能测试代码，以避免不必要的输出。
在这种情况下，考虑filenames_range_mapper的一个稍微不同的实现就足够了，在这个实现中，值将只是一个整数列表（而不是PdfReader对象）。

def filenames_range_mapper_tester(pdf_r:PdfReader, page_indices:dict) -> dict:
    num_pages = list(page_indices.values()) + [len(pdf_r.pages)+1] # add last page as well
    # slice the pages from the reader object
    return {name: list(range(len(pdf_r.pages)))[start,end] for name, start, end in zip(page_indices, num_pages, num_pages[1:])}

# auxiliary test
file_name = "./report1.pdf"
pdf_r = PdfReader(open(file_name, "rb"))
page_breaks = page_breaks(pdf_r)
mapper = filenames_range_mapper_tester(pdf_r, page_breaks)

template_output = './zp_{}.pdf'
for name, pages in mapper.items():
   print(template_output.format(name.title()), pages)

如果输出有意义，那么您可以继续使用非测试代码。
关于如何获得正确页面的抽象：

# mimic return of "page_breaks"
page_breaks = {
    "RIVIERA": 1,
    "ACQUAROSSA": 4,
    "BLENIO": 6,
    "BELLINZONA": 11
}

# mimic "filenames_range_mapper"
last_page_of_pdf = 12 + 1 # increment by 1 the number of pages of the pdf!

num_pages = list(page_breaks.values()) + [last_page_of_pdf]
#[1, 4, 6, 11, 12]

mapper = {name: list(range(start, end)) for name, start, end in zip(page_breaks, num_pages, num_pages[1:])}
#{'RIVIERA': [1, 2, 3],
# 'ACQUAROSSA': [4, 5],
# 'BLENIO': [6, 7, 8, 9, 10],
# 'BELLINZONA': [11, 12]}

@卡片
我做了你在评论中建议的测试。
我发布代码是为了确保我已经用正确的方式进行了测试。我运行的代码正是：

from PyPDF2 import PdfWriter, PdfReader

def page_breaks(pdf_r:PdfReader) -> dict:
    page_breaks = {}
    for i in range(len(pdf_r.pages)):
        pdf_text = pdf_r.pages[i].extract_text() 
        for municipality in array_merged_zone_send:
            pattern = f'PANORAMICA DI {municipality.upper()}'
            if re.search(pattern, pdf_text):
                page_breaks[municipality] = i
    return page_breaks

def filenames_range_mapper_tester(pdf_r:PdfReader, page_indices:dict) -> dict:
    num_pages = list(page_indices.values()) + [len(pdf_r.pages)+1] # add last page as well
    # slice the pages from the reader object
    return {name: list(range(len(pdf_r.pages)))[start,end] for name, start, end in zip(page_indices, num_pages, num_pages[1:])}

# auxiliary test
file_name = "./report1.pdf"
pdf_r = PdfReader(open(file_name, "rb"))
page_breaks = page_breaks(pdf_r)
mapper = filenames_range_mapper_tester(pdf_r, page_breaks)

template_output = './zp_{}.pdf'
for name, pages in mapper.items():
   print(template_output.format(name.title()), pages)

测试在位置“num_pages=....."处出现错误。

File "<string>", line 15, in filenames_range_mapper_tester
TypeError: 'list' object is not callable

一些观察：我还不明白，在上述代码中，您如何具有：

def filenames_range_mapper_tester(pdf_r:PdfReader, page_indices:dict) -> dict:
    num_pages = list(page_indices.values()) + [len(pdf_r.pages)+1]

我在你的代码中找遍了所有地方，但是我没有找到之前“page_indices”定义的痕迹。在应用方法“values（）"之前，你在哪里定义了“page_indices”？
在answer中，您确认了abstractionpage_indexs =page_breaks，然后为什么不以这种方式插入代码：

def filenames_range_mapper_tester(pdf_r:PdfReader, page_breaks:dict) -> dict:
    num_pages = list(page_breaks.values()) + [len(pdf_r.pages)+1] # add last page as well
    # slice the pages from the reader object
    return {name: list(range(len(pdf_r.pages)))[start,end] for name, start, end in zip(page_breaks, num_pages, num_pages[1:])}

如果你使用page_breaks，这个“page_breaks”已经从函数def page_breaks的结果中定义了，所以你用一个之前定义的方法来应用，但是即使我用page_breaks替换page_indices，错误还是一样的。