Python Forum

I have three dictionaries with coordinates looking like this:

First one one_crime_cord Containing a unique crime

(34.0141, -118.2978)

Second one crime_cord Containing multiple crimes

{0: (34.0141, -118.2978), 1: (34.0459, -118.2545), 2: (34.1847, -118.44)}

Third one neigh_cord Containing multiple neighborhoods

{'Acton': (34.497355239240854, -118.1698101922935), 'Adams-Normandie': (34.03146149912416, -118.30020800000014), 'Agoura Hills': (34.146736499122795, -118.75988450000015)}

I am trying to set a nested loop to get the distances from every crime to every neighborhood, and then input on an external data frame the neighborhood each crime belongs to based on the minimum distance.
So far, I've been able to do it for a single crime with these lines of code:
First Line of Code:

d3=[]
n_name=[]
for neigh_name, coord in neigh_cord.items():
    d2=distance (one_crime_coord,coord).m
    n_name.append(neigh_name)
    d3.append(d2)
    print(neigh_name,d2)

Output:

Acton           54886.9994821537
Adams-Normandie 1938.5858465073106
Agoura Hills    45115.60137307561

Second Line of Code:

distan_df=pd.DataFrame()
distan_df['Neighborhood_Name']=n_name;
distan_df['Distance to Crime']=d3
print(min(d3))
distan_df
index_min = np.argmin(d3)
print('------')
print('The Crime was commited in the neighborhood:')
print(distan_df.iloc[index_min,0])

Output:

472.2815720091788
------
The Crime was commited in the neighborhood:
Exposition Park

Third Line of Code:

test=la_crime_refined.copy()
test['Neighborhood']=''
test.head()
test.at[index_min,'Neighborhood']= distan_df.iloc[index_min,0]
display(test.iloc[index_min])

With the output in the data frame I'm trying to populate of:

	Neighborhood
83	Exposition Park

I figured I could do something similar using a nested loop:

distan_matrix=pd.DataFrame()
n_name2=[]
d5=[]
for crime_no,crime_cord in crime_cord.items():
    for neigh_name, coord in neigh_cord.items():
        d4=distance (crime_cord,coord).m
        n_name2.append(neigh_name)
        d5.append(d4)
    distan_matrix=pd.DataFrame()
    distan_matrix['Neighborhood_Name']=n_name2;
    distan_matrix['Distance to Crime']=d4
    index_min = np.argmin(d4)
    test.at[index_min,'Neighborhood']= distan_matrix.iloc[index_min,0]
    
print('------')
print('All Crimes have been assigned to a neighborhood')
test.head()

**The desired output would be a filled 'Neighborhood' column in test df**

	Neighborhood
1	North Holywood
2   Woodland Hills
3   Topanga Canyon
.
.
.
83  Exposition Park
.
.
.

However, I am not able to make it work. Is it because I'm using the outer loop variable in the inner loop? any suggestions? This is the error I'm obtaining:

File "<ipython-input-57-8379f4221588>", line 4
    for crime_no,crime_cord in crime_cord.items()
                                                 ^
SyntaxError: invalid syntax

Thank you and sorry for the length of the question!

Are you missing a colon in line 4?

(Nov-24-2020, 03:29 PM)palladium Wrote: [ -> ]Are you missing a colon in line 4?

Yes, I was! There is no error now, but it becomes an infinite loop Any ideas?

Can you show a subset of the infinite loop, as well as the code with all the imports (what is the function distance()?) and a subset of data so that we can run the code?