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shoggananna
shoggananna

Reputation: 565

how to find index of a string after the execution of the startswith() method

I want to search through a column until I find the str Linear, find the index of this location, add 1 to it and then extract a dataframe via slicing.

I have tried the following

for sheet_name, df in Input_Data.items():
    for line in sheet_name:
        if line.startswith('Linear'):
            index = line.index('Linear')
            break
    df1 = df[index+1:236]
    df1.loc[:,'Unnamed: 26']*=-1  
    df1.loc[:,'Unnamed: 27']*=-1
    df=df1.sort_index(ascending=False)
    Indexer=df.columns.tolist()
    df = [(pd.concat([df[Indexer[0]],df[Indexer[num]]],axis=1)) for num in [1,2,3,4,5,6]]#concatenation
    df = [(df[num].astype(str).agg(','.join, axis=1)) for num in [0,1,2,3,4,5]]
    df=pd.DataFrame(df)
    df=df.loc[0].append(df.loc[1].append(df.loc[2].append(df.loc[3].append(df.loc[4].append(df.loc[5])))))

However my 'index' is returning 0 where in fact it should be 125....

Upvotes: 0

Views: 571

Answers (2)

xtofl
xtofl

Reputation: 41519

If line.startswith('Linear'), 'Linear' will be the first word in line.

If what you want is the line number, you can try finding it; enumerate is your friend.

def find_index_of(lines, predicate):
  for index, line in enumerate(lines):
    if predicate(line):
      return index

index = find_index_of(sheetname, lambda x: x.startswith("Linear"))

Upvotes: 1

Uriya Harpeness
Uriya Harpeness

Reputation: 628

The first check you do it startswith, meaning the string begins with the argument - index 0 and forward, so index will always be 0 in that case.

I think the loop you're looking for is with a range, or index number, to find the line that starts with that string, and refer to all the lines after that line.

for index in range(len(sheet_name)):
    if sheet_name[index].startswith('Linear'):
        df1 = df[index+1:236]
        break

Upvotes: 0

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