import pandas as pd

# You don't need these two lines
# as you already have your DataFrame in memory
df = pd.read_csv("nor.txt", sep="|")
df.drop(df.columns[-1], axis=1)

# Get column names
cols = df.columns

# Create a new DataFrame with just the markdown
# strings
df2 = pd.DataFrame([['---',]*len(cols)], columns=cols)

#Create a new concatenated DataFrame
df3 = pd.concat([df2, df])

#Save as markdown
df3.to_csv("nor.md", sep="|", index=False)