Changing a string value to a numerical value using python code and a lamda function

[deanhystad]

I think you are missing that df is a dataframe. This does not work because df["State"] is a series, not an element of a list or value in a dictionary.

import pandas as pd
df = pd.DataFrame({"State": ["NORMAL", "BROKEN"]})
df["label"] = 0 if df["State"] == "NORMAL" else 1

Error:
Traceback (most recent call last):
  File "...", line 3, in <module>
    df["label"] = 0 if df["State"] == "NORMAL" else 1
        ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

"put your one-liner in some kind of loop" is essentially what "map()" and apply() are doing