Pytrends Multiple geo codes

I use the codes below to export the number of searches for multiple states in US and get the error "ResponseError: The request failed: Google returned a response with code 400."

from pytrends.request import TrendReq
import pandas as pd
import time
startTime = time.time()
pytrend = TrendReq(hl='en-US', tz=360)

colnames = ["keywords"]
df = pd.read_csv("keyword_list.csv", names=colnames)
df2 = df["keywords"].values.tolist()
df2.remove("Keywords")

dataset = []

for x in range(0,len(df2)):
     keywords = [df2[x]]
     pytrend.build_payload(
     kw_list=keywords,
     cat=0,
     timeframe='2020-01-01 2020-02-01',
     geo='US-MA,US-TX,US-NY,US-WA')
     data = pytrend.interest_over_time()
     if not data.empty:
          data = data.drop(labels=['isPartial'],axis='columns')
          dataset.append(data)

result = pd.concat(dataset, axis=1)
result.to_csv("US.csv")

Issue is with the geo parameter, You can provide one at a time not all, You can try like this

from pytrends.request import TrendReq
import pandas as pd
import time
startTime = time.time()
pytrend = TrendReq(hl='en-US', tz=360)

colnames = ["keywords"]
df = pd.read_csv("keyword_list.csv", names=colnames)
df2 = df["keywords"].values.tolist()
df2.remove("Keywords")

dataset = []
for geo_code in ['US-MA','US-TX','US-NY','US-WA']:
    for x in range(0,len(df2)):
        keywords = [df2[x]]
        pytrend.build_payload(
        kw_list=keywords,
        cat=0,
        timeframe='2020-01-01 2020-02-01',
        geo=geo_code)
        data = pytrend.interest_over_time()
        if not data.empty:
            data = data.drop(labels=['isPartial'],axis='columns')
            data['geo']=geo_code
            dataset.append(data)

result = pd.concat(dataset)
result.to_csv("US.csv")