Create network graph using networkx

networkx.py

#Create the network graph using networkx
if uploaded_file is not None:     
    df=pd.read_csv(uploaded_file)  
    A = list(df["Source"].unique())
    B = list(df["Target"].unique())
    node_list = set(A+B)
    G = nx.Graph() #Use the Graph API to create an empty network graph object
    
    #Add nodes and edges to the graph object
    for i in node_list:
        G.add_node(i)
    for i,j in df.iterrows():
        G.add_edges_from([(j["Source"],j["Target"])])    
 
    #Create three input widgets that allow users to specify their preferred layout and color schemes
    col1, col2, col3 = st.columns( [1, 1, 1])
    with col1:
        layout= st.selectbox('Choose a network layout',('Random Layout','Spring Layout','Shell Layout','Kamada Kawai Layout','Spectral Layout'))
    with col2:
        color=st.selectbox('Choose color of the nodes', ('Blue','Red','Green','Orange','Red-Blue','Yellow-Green-Blue'))      
    with col3:
        title=st.text_input('Add a chart title')

    #Get the position of each node depending on the user' choice of layout
    if layout=='Random Layout':
        pos = nx.random_layout(G) 
    elif layout=='Spring Layout':
        pos = nx.spring_layout(G, k=0.5, iterations=50)
    elif  layout=='Shell Layout':
        pos = nx.shell_layout(G)            
    elif  layout=='Kamada Kawai Layout':
        pos = nx.kamada_kawai_layout(G) 
    elif  layout=='Spectral Layout':
        pos = nx.spectral_layout(G) 

    #Use different color schemes for the node colors depending on he user input
    if color=='Blue':
        colorscale='blues'    
    elif color=='Red':
        colorscale='reds'
    elif color=='Green':
        colorscale='greens'
    elif color=='Orange':
        colorscale='orange'
    elif color=='Red-Blue':
        colorscale='rdbu'
    elif color=='Yellow-Green-Blue':
        colorscale='YlGnBu'

    #Add positions of nodes to the graph
    for n, p in pos.items():
        G.node[n]['pos'] = p