df1 = pd.read_csv('C:\path\my.csv', header=0)#.set_index('name1')
df2 = df1.assign(soundexMd5=jellyfish.soundex(str(df1['name1'])))
#df2 = df1.assign(soundexMd5=lambda x: jellyfish.soundex(str(df1['name1'])))
#df2 = df1.assign(soundexMd5=lambda x: jellyfish.soundex(str(x.name1)))
print(df2)

"name1"
"Yolanda"
"Push Notify"
"Yolanda"
"test1"
"test2"

name1 soundexMd5
0                     Yolanda       0453
1                 Push Notify       0453
2                     Yolanda       0453
3                       test1       0453
4                       test2       0453

df1 = pd.read_csv('C:\path\my.csv', header=0)
df2 = df1.assign(soundexMd5=df1['name1'].apply(jellyfish.soundex))

df2 = df1.assign(soundexMd5=df1['name1'].astype(str).apply(jellyfish.soundex))