Python——为什么条件在一个函数中执行而在另一个函数中不执行？

我是 Python 初学者。我正在尝试编写一些基本代码来自动化一个简单但重复的工作过程，但被这个问题难住了。

# Prior to the code block below, a csv file import would have created the a and ag variables with their respective numerical values.

high = list(range(66, 99))
mod = list(range(36, 65))
low = list(range(1,35))
verysiggap = list(range(61, 99))
siggap = list(range(31, 60))
nonsiggap = list(range(1, 30))

fco_output_list = []

def fco_block1(*args):
    if a in high and ag in high:
        print("Both a and ag are high!")
        fco_output_list.append("fco1")
    if a in high and ag in high and a-ag in nonsiggap:
        fco_output_list.append("foc2")

fco_block1(a, ag)

a_ag_combi_output = 0
a_ag_gap_output = 0

def fco_block2(*args):
    global a_ag_combi_output
    if a in high and ag in high:
        a_ag_combi_output = 0
    elif a in high and ag in low or ag in mod:
        a_ag_combi_output = 1
    elif a in mod and ag in low:
        a_ag_combi_output = 2
    elif ag in high and a in low or a in mod:
        a_ag_combi_output = 3
    elif ag in mod and a in low:
        a_ag_combi_output = 4
    elif a in low and ag in low:
        a_ag_combi_output = 5
    global a_ag_gap_output
    if a in high and ag in high and a-ag in nonsiggap:
        a_ag_gap_output = 1

fco_block2(a, ag)

# There are some simple print functions after the code above that tell me very clearly that fco_block2 executed without any issues. 

至于 fco_block1 的执行，没有错误消息，但条件似乎没有执行。根据导入的 a 和 ag 值，fco_output_list 应该由 fco1 和 fco2 填充，但事实并非如此。

为什么会这样？我觉得这很奇怪，尤其是当 block1 中的条件语句的措辞与 block2 中的相应条件相同，但是 block2 中的那些被执行而不是 block1 中的那些？