Python：变量初始化和for循环

Question

我有一个int的列表，范围从0到99，例如center_nodes=[51,52]，我想执行一个简单的操作：

取第一个元素center_nodes[0]，得到它的第一个数字first=str(center_nodes[0])[0]，然后根据数字本身添加一个int。

示例：如果 first=5，则 result=int(center_nodes[0])+int(first)。在这种情况下，它应该产生 56.

我写了一段代码来做到这一点，但我总是得到 0。我一定犯了一些非常愚蠢的错误，我怀疑它在于 result 变量的初始化，该变量在脚本中称为 grid_coord.

我的尝试：

#code block to compute the center_nodes[] list
#here comes my script:
first=str(center_nodes[0])[0] #Get the first figure of element 0 of center_nodes
print('first figure: '+str(first))
grid_coord=None
if len(str(center_nodes[0]))==1: #Check if center_nodes[0] is in the 0-9 range
    grid_coord=int(first)
    print('Grid coord for center giant comp is: '+str(grid_coord))
elif len(str(center_nodes[0]))==2: #Check if center_nodes[0] is in the 10-99 range
    if first==1: #Checks the first digit of center_nodes[0] and then adds it to int(center_nodes[0])
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==2: #Check the second digit...
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==3: #Check the third digit...
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==4: #4th
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==5: #5th
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==6: #6th
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==7: #7th
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==8: #8th
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))
    if first==9: #9th and last
        grid_coord=int(center_nodes[0])+int(first)
        print('Grid coord for center giant comp is: '+str(grid_coord))

对于center_nodes=[51,52]，我应该得到grid_coord=56，但我得到的却是grid_coord=0。我应该改变什么？

Answer 1

如果我的理解是正确的，你需要像这样：

l = [51, 52, 83]

for item in l:
    newItem = int(str(item)[0]) + item
    print newItemt

Answer 2

first=str(center_nodes[0])[0] #Get the first figure of element 0 of center_nodes
grid_coord=None
if len(str(center_nodes[0]))==1: #Check if center_nodes[0] is in the 0-9 range
    grid_coord=int(first)
    print('Grid coord for center giant comp is: '+str(grid_coord))
elif len(str(center_nodes[0]))==2: #Check if center_nodes[0] is in the 10-99 range
    grid_coord=int(center_nodes[0])+int(first)
    print('Grid coord for center giant comp is: '+str(grid_coord))

Python：变量初始化和for循环

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