Arnold Klein questions

• Find the common string in a subgroup in a list in Python
• Side-by-side boxplots with Pandas
• Flatten nested pandas dataframe
• send an image (as numpy array) 'requests.post'
• find rows with k-consecutive NaNs in Pandas
• random sampling with Pandas data frame disjoint groups
• Searching for all matches in texts with Pandas
• Search for a pattern in numpy array
• Select rows in Pandas which does not contain a specific character
• Convolutional neural network architectures with an arbitrary number of input channels (more than RGB)

Arnold Klein answers