python嵌套循环列表

Question

I am currently stuck at one nested loop problem. I would appreciate it greatly if anyone can offer their insight or tips on how to solve this sticky problem that i am facing.

I am trying to append some values to a list in a for loop. I succeeded in doing that. But how can I get the last list as my variable to use in another loop?

Lets say. I am extracting something by appending them in a list in a for loop.

a=list()
for b in hugo:
    a.append(ids)
    print(a)

gives me

[1]
[1,2]
[1,2,3]
[1,2,3,4]

But I only need the last line of the list as my variable to be used in another for loop. Can anybody gives me some insights how to do this? Your help is much appreciated. Thanks in advance.

Edit:

Actually I am not trying to get someone to do my homework for me. I am just testing some software programming using python. Here goes:

I am trying to write a script to extract files with the end name of .dat from ANSA pre-processor with the correct name and file ID

For example:

ID       Name
1        hugo1.dat
8        hugo2.dat
11       hugo3.dat
18       hugo4.dat

Here is what I have written:

import os
import ansa
from ansa import base
from ansa import constants
from ansa import guitk

def export_include_content():
  directory = gutik.UserInput('Please enter the directory to Output dat files:')
  ishow=list()
  includes=list()
  setna=list()
  iname=list()

# Set includes variables to collect the elements from a function known as "INCLUDE" from the software
includes=base.CollectEntitites(deck, None, "INCLUDE")

# For loop to get information from the "INCLUDE" function with the end filename ".dat"
for include in includes:
    ret=base.GetEntityCardValues(deck, include, 'NAME', 'ID')
    ids=str(ret['ID'])
    setname=ret['NAME']
    if setname.endswith('dat'):
        ishow.append(ids)
        iname.append(setname)

# Print(ishow) gives me
[1]
[1,8]
[1,8,11]
[1,8,11,18]

# print(iname) gives me
[hugo1]
[hugo1,hugo2]
[hugo1,hugo2,hugo3]
[hugo1,hugo2,hugo3,hugo4]

# Now that I got both of my required list of IDs and Names. It's time for me to save the files with the respective IDs and Names.

for a in ishow:
        test=base.GetEntity(deck,'INCLUDE',int(a))
        print(a)
        file_path_name=directory+"/"+iname
        print(file_path_name)

#print(a) gives me
1
8
11
18

#print(file_path_name) gives me
filepath/[hugo1,hugo2,hugo3,hugo4]
filepath/[hugo1,hugo2,hugo3,hugo4]
filepath/[hugo1,hugo2,hugo3,hugo4]
filepath/[hugo1,hugo2,hugo3,hugo4]

# This is the part I got stuck. I wanted the output to be printed in this order:

1
filepath/hugo1

8
filepath/hugo2

11
filepath/hugo3

18
filepath/hugo4

But it doesnt work well so far for me, that's why I am asking whether you all can provide me some assistance on solving this problem :) Helps appreciated!! Thanks all

Answer 1

Your problem is with the code indent:

a=list()
for b in hugo:
    a.append(ids)
print(a)

Answer 2

Use a dictionary instead of having 2 separate list for ids and names of includes The code below creates a dictionary with include id as keys and the corresponding include's name as the value. later this dict is used to print file name

In case you want to save each include as separate file,First isolate the include using "Or"(API) then we have an API for each deck in ANSA to do save files(make sure to enable optional argument 'save visible').for example for NASTRAN it is OutputNastran you can search it in the API search tab in the script editor window

dict={}
for include in includes:
    ret=base.GetEntityCardValues(deck, include, 'NAME', 'ID')
    ids=str(ret['ID'])
    setname=ret['NAME']
    if setname.endswith('.dat'):
        dict[ids]=setname
for k, v in dict.items():
   test=base.GetEntity(deck,'INCLUDE',int(k))
   file_path_name=directory+"/"+v
   print(file_path_name)

Hope this helps

Answer 3

Your current code has the loop printing every single time it iterates through, so move the print statement left to the same indent level as the for loop, so it only prints once the for loop has finished running its iterations.

a=list()
for b in hugo:
    a.append(ids)
print(a)

Answer 4

Assuming ids is actually just the elements in hugo:

a=[id for id in hugo]
print(a)

Or

a=hugo.copy()
print(a)

Or

print(hugo)

Or

a=hugo
print(a)

Or

string = "["
for elem in hugo:
  string.append(elem + ",")
print(string[:-1] + "]")

Edit: Added more amazing answers. The last is my personal favourite.

Edit 2:

Answer for your edited question:

This part

for a in ishow:
    test=base.GetEntity(deck,'INCLUDE',int(a))
    print(a)
    file_path_name=directory+"/"+iname
    print(file_path_name)

Needs to be changed to

for i in range(len(ishow)):
    test=base.GetEntity(deck,'INCLUDE',int(ishow[i]))
    file_path_name=directory+"/"+iname[i]

The print statements can be left if you wish.

When you are trying to refer to the same index in multiple lists, it is better to use for i in range(len(a)) so that you can access the same index in both.