我如何遍历以逗号分隔的字符串中的每个条目，并使用 Python 将其作为单独的输入包含在内

Question

I have a string called listnumber

listnumbers
'1.0,2.0,3.0,4.0,5.0,6.0'

I have a function that returns each value of that string

def myfun(lists): 
   return ','.join([i for i in lists.split(',')])

When i type the function

myfun(listnumbers)
'1.0,2.0,3.0,4.0,5.0,6.0'

I have a loop script

aprx = arcpy.mp.ArcGISProject("CURRENT")
m = aprx.listMaps("Map")[0]
for lyr in m.listLayers("OMAP_PCT_POP_ACS17"):
   if lyr.supports("DEFINITIONQUERY"):
       lyr.definitionQuery="Value=" ""+myfun(listnumbers)+""

I end up getting

Value=1.0,2.0,3.0,4.0,5.0,6.0

What i would really like is for this to loop and give me

Value=1.0
Value=2.0
Value=3.0

and so on...... As separate entries. I feel i am very close i just need to make some changes.

Answer 1

Instead of joining the string back together, just leave it apart:

def myfun(lists): 
   return [i for i in lists.split(',')]

Then, in your loop, you should loop through the values of the list returned by myfun :

aprx = arcpy.mp.ArcGISProject("CURRENT")
m = aprx.listMaps("Map")[0]
for lyr in m.listLayers("OMAP_PCT_POP_ACS17"):
   if lyr.supports("DEFINITIONQUERY"):
       for value in myfun(listnumbers):
           lyr.definitionQuery = "Value=" + value

However, str.split already does what this improved myfun does, since it already returns a list. Thus, you can simplify even further and get rid of myfun entirely:

aprx = arcpy.mp.ArcGISProject("CURRENT")
m = aprx.listMaps("Map")[0]
for lyr in m.listLayers("OMAP_PCT_POP_ACS17"):
   if lyr.supports("DEFINITIONQUERY"):
       for value in listnumbers.split(','):
           lyr.definitionQuery = "Value=" + value