I have two lists and I want to take item names from the list and use it to a loop. Please see the codes below.

df_compressed_list= ['df_compressed_1','df_compressed_2','df_compressed_3','df_compressed_4','df_compressed_5','df_compressed_6','df_compressed_7','df_compressed_8','df_compressed_9','df_compressed_10','df_compressed_11','df_compressed_12','df_compressed_13','df_compressed_14']

plot_image_list= ['compressed_1','compressed_2','compressed_3','compressed_4','compressed_5','compressed_6','compressed_7','compressed_8','compressed_9','compressed_10','compressed_11','compressed_12','compressed_13','compressed_14']

for i in df_compressed_list:
    plt.figure(100,figsize=(10,5))
    plt.plot(df_compressed_list[i]['time'], df_compressed_list[i]['voltage'])
    for j in plot_image_list:
        plt.savefig('images\[plot_image_list][j].PNG')
    plt.close()

['time'] and ['voltage'] are columns names of a pandas dataframe.I already created dataframe with respective names. I tried the above code but it doesn't work. There is definitely something wrong with my code but I can't figure out what. It shows

TypeError: list indices must be integers or slices, not str

What I want it to do is, it will take the name one by one from the list and put the name in plt.plot(df_compressed_list[i]['time'], df_compressed_list[i]['voltage'])

and plt.savefig('images\[plot_image_list][j].PNG') so that it would look like this

plt.plot(df_compressed_1['time'], df_compressed_1['voltage'])

 plt.savefig('images\compressed_1.PNG')

CodePudding user response：

In this line you trying to excess a list by using keys.

plt.plot(df_compressed_list[i]['time'], df_compressed_list[i]['voltage'])

Maybe your problem is, that instead of df_compressed_list[i]['time'] you want to excess your dataframe like this PANDAS_DATAFRAME[i]['time']

CodePudding user response：

1. Elements of df_compressed_list are strings, not dataframes.
2. Thus, the i in for i in df_compressed_list:, being an element of the list (not an index into df_compressed_list!), is a string.
3. Then, df_compressed_list[i] attempts to index the list with this string.
4. This an error since "list indices must be integers or slices, not str".

You could fix this by replacing for i in df_compressed_list: by for i, _ in enumerate(df_compressed_list):, but then there'd be more errors:

1. Elements of df_compressed_list are strings, not dataframes.
2. Thus, df_compressed_list[i] would be a string.
3. So, df_compressed_list[i]['time'] would attempt to index this string with another string, 'time'.
4. This is also an error because string indices must be integers, not strings.