I have code which is supposed to grab a YAML file and read it in, (does successfully), but is also supposed to be able to update the YAML return one of three options:
The second and third options works well, but the first is returning TypeError: string indices must be integers or TypeError: 'int' object is not iterable whenever I update any values outside of the nested dictionaries in my dictionary d.
Here is the code I came up with:
class YAML_Config:
'''
Class used to interact with .YAML filetypes. Allows the creation of objects \
that can be manipulated and save certain YAML files and configuration settings.
'''
def __init__(self, filename):
'''
Initial defintion. Defines the location for saving a new .YAML file or for loading \
a previous one. The dictionary corresponding to the .YAML file is saved to self.dict. \
If this is a new .YAML file, an empty dictionary is created.
Input Arguments:
-filename: (string) The name of the file where the current .YAML file is \
located or the new .YAML will be saved.
'''
#Get the filename and save it to the class as a property.
self.file = filename
#Check if the file exists...
if os.path.isfile(self.file):
#Prepare to open the file with reading capabilities
with open(self.file,'r') as infile:
#Get a dictionary with all of the YAML informatin.
yaml_dict = yaml.load(infile)
#If the file does not exist...
else:
#Create an empty dictionary to save all YAML data.
yaml_dict = {}
#Create an empty .yaml file with the dictionary.
with open(self.file, 'w') as infile:
#Save updated dictionary to YAML file.
yaml.dump(yaml_dict, infile, default_flow_style=False)
print('YAML configuration file not found. New, empty dictionary, and .yaml file created.')
self.dict=yaml_dict
def update_value(self, kwargs):
'''
Used to update YAML files, and checks that the files were updated properly.
'''
#If these are not keyword arguments, then throw an error.
assert kwargs, 'Input Error'
#Get the YAML dictionary before it is updated.
yaml_dict = self.dict
#Make a copy of the dictionary to compare against later.
yaml_dict_original = copy.deepcopy(self.dict)
#Check if the dictionary is nonetype. This happens if the file is new as the file is empty.
if yaml_dict_original is None:
#Redefine orginal dictionary as an empty dictionary.
yaml_dict_original={}
#The new dictionary will simply be what is passed to the function.
yaml_dict=kwargs
else:
#Update the original dictionary and update it with the arguments passed.
#This also updates self.dict as yaml_dict is simply a reference to
#that dictionary, not a copy of it.
yaml_dict.update(kwargs)
#Check if changes were made
if (yaml_dict==yaml_dict_original) is False:
#Open the YAML file to write to it.
with open(self.file, 'w') as outfile:
#Save updated dictionary to YAML file.
yaml.dump(self.dict, outfile, default_flow_style=False)
#Check that the file actually updated properly:
#Double-check the file that it actually updated.
with open(self.file, 'r') as infile:
lastupdate = yaml.load(infile)
#Get any nonmatching values between what should be in the YAML file and what actually is.
errors = { k : yaml_dict[k] for k in set(yaml_dict) - set(lastupdate) }
#Find out what changed in the YAML file.
edits = { k : yaml_dict_original[k] for k in set(yaml_dict_original) - set(lastupdate) }
#Check if errors is not empty. Evaluating dictionaries as boolean either returns True (not empty)
#or False (empty).
if bool(errors) is True:
#First line of return print statement.
print('The following entries did not update successfully:')
#Loop through keys in errors
for n in errors:
#Print the current key
print (n)
#Loop through entries of current key
for m in errors[n]:
#Print current entry of current key
print (m,':',errors[n][m])
#Saved properly, check for edits and display to user.
else:
#Find where any edits were made.
edits = {k: yaml_dict_original[k] for k in yaml_dict_original if k in lastupdate and yaml_dict_original[k] != lastupdate[k]}
#Show user what edits were successfuly made.
print('%s was successfully updated with the following changes:' % os.path.basename(self.file))
#Loop through keys in edits
for n in edits:
#Print the current key
print (n)
#Loop through entries of current key
for m in edits[n]:
#Print current entry of current key
print (m,':',edits[n][m])
#If no changes were made...
else:
#Show user what edits were successfuly made.
print('No changes to %s were passed. File not updated.' %
os.path.basename(self.file))
test=YAML_Config(r'...Path\Python Work\yaml_test.yaml')
d = {'A': 7, 'B':{'C':'D', 'D':False, 'E':'Julio'},\
'The Real C': {'J?':'Yes, this is J.', 'K' : 241},'Q' : 'PQ'}
test.update_value(d)
First Error Section:
b = {'A': '', 'B':{'C':'D', 'D':False, 'E':'Julio'},\
'The Real C': {'J?':'Yes, this is J.', 'K' : 241},'Q' : 'PQ'}
#TypeError: string indices must be integers.
test.update_value(b)
Second Error Section:
f = {'A': 7, 'B':{'C':'D', 'D':False, 'E':'Julio'},\
'The Real C': {'J?':'Yes, this is J.', 'K' : 241},'Q' : 2}
#TypeError: 'int' object is not iterable.
test.update_value(f)
The YAML file updates every time I run this code. So the actual updating is working, but I'm not really sure why I can't find the indices of the dictionary updates. I'm a little rusty on my Python, and new to YAML, so I may be missing something obvious here.
I'm using Python 3.6.5.
Your code goes wrong on this line:
# Loop through entries of current key
for m in edits[n]:
and at that point edits is a dict: {A: 7} (as A is the key with a changed value). Your code seems only to anticipate a change in a complex value (like the one for B), because if you would have done:
b = {'A': 7, 'B':{'C':'D', 'D':True, 'E':'Julio'},\
'The Real C': {'J?':'Yes, this is J.', 'K' : 241},'Q' : 'PQ'}
you get:
test.yaml was successfully updated with the following changes:
B
C : D
D : False
E : Julio
So you should rethink your "reporting" and update it to something that can not only handle values that are dicts , but also lists and primitives (YAML scalars: string, int, boolean, etc.):
# Show user what edits were successfuly made.
print('{} was successfully updated with the following changes:'.format(os.path.basename(self.file)))
# Loop through keys in edits
for n in edits:
# Loop through entries of current key
if isinstance(edits[n], dict):
# Print the current key
print(n)
for m in edits[n]:
# Print current entry of current key
print(m, ':', edits[n][m])
elif isinstance(edits[n], list):
# Print the current key followed by the elements
print(n)
for m in edits[n]:
# Print current entry of current key
print('- ', [m])
else: # scalar
print('{}: {}'.format(n, edits[n]))
and then your output will be:
test.yaml was successfully updated with the following changes:
A: 7
test.yaml was successfully updated with the following changes:
A:
Q: PQ
(assuming you run the two extra updates after each other).