[dywang@deyu zzz]$ cat dict2.py
#!/usr/bin/python3
# coding: utf-8
uid = { 'dywang':1000, 'david':2346, 'linda':1324 }
print("uid =", uid)
uid['peter'] = 1202
print("uid =", uid)
[dywang@dywIssd zzz]$ ./dict2.py
uid = {'dywang': 1000, 'david': 2346, 'linda': 1324}
uid = {'dywang': 1000, 'david': 2346, 'linda': 1324, 'peter': 1202}