Question

这是我的代码。我只想在名为＆＃34; country＆＃34;的字典中记录该值。当键，字典中不存在值。为此，我正在检查关键字不在（第二行代码）。但是，它不起作用。即使字典中存在密钥，它也会更新值。任何帮助都会非常感激。

df = pd.DataFrame()
country = dict()

for file in allFiles:

   df = pd.read_excel(file,'Internal', skiprows = 7)
   print ("file name is " + file)

   if(df.loc[1][0] ==  "Country:"):
      key = df.loc[1][1]
      value = df.loc[2][1]
   else:
      key = df.loc[2][1]
      value = df.loc[1][1]

   print ('key is ' , key)
   print ('value is ' , value)

   try:
       print (df.loc[47][2], df.loc[47][3])
       print (df.loc[49][2], df.loc[49][3])

   except Exception as inst:
       print (type(inst))
       print (inst.args)
       print (inst)


   if ((key not in country) or (value != 'nan')):
      country[key] = value

Answer 1

从

改变你的状况

# Even if 'key' was already in 'country', If (value != 'nan')
# evaluated to 'True', the update will happen
if ((key not in country) or (value != 'nan')):

到

# Do not update unless 1- the key does not exist AND 2- value is not 'nan'
if (key not in country) and (value != 'nan'):

由于value（很可能）不是nan，因此记录将始终更新。

不在for dict（）不起作用

1 个答案: