pandas save numeric value as string code example
Example 1: pandas - from umeric to string
df['A'] = df['A'].apply(str)
Example 2: change value to string pandas
mtrx['X.3'] = mtrx['X.3'].astype(str)
df['A'] = df['A'].apply(str)
mtrx['X.3'] = mtrx['X.3'].astype(str)