If I have a list in python, is there a function to tell me if all the items in the list are strings?
For Example: ["one", "two", 3] would return False, and ["one", "two", "three"] would return True.
asked May 21, 2016 at 0:49
1
Just use all[] and check for types with isinstance[].
>>> l = ["one", "two", 3]
>>> all[isinstance[item, str] for item in l]
False
>>> l = ["one", "two", '3']
>>> all[isinstance[item, str] for item in l]
True
answered May 21, 2016 at 0:50
TigerhawkT3TigerhawkT3
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3
Answering @TekhenyGhemor's follow-up question: is there a way to check if no numerical strings are in a list. For example: ["one", "two", "3"] would return false
Yes. You can convert the string to a number and make sure that it raises an exception:
def isfloatstr[x]:
try:
float[x]
return True
except ValueError:
return False
def valid_list[L]:
return all[[isinstance[el, str] and not isfloatstr[el]] for el in L]
Checking:
>>> valid_list[["one", "two", "3"]]
False
>>> valid_list[["one", "two", "3a"]]
True
>>> valid_list[["one", "two", 0]]
False
In [5]: valid_list[["one", "two", "three"]] Out[5]: True
answered May 21, 2016 at 4:39
NeapolitanNeapolitan
2,0018 silver badges20 bronze badges
Another way to accomplish this is using the map[] function:
>>> all[map[lambda x: isinstance[x, str], ['one', 'two', 3]]]
False
>>> all[map[lambda x: isinstance[x, str], ['one', 'two', 'three']]]
True
answered Mar 13 at 3:16
In this article we will dicuss different ways to check if all element in a given List are same or matches a condition. Suppose we have a list of string i.e. Now let’s use python all[] function to check if all elements in the given list are same. Python all[] function checks if all Elements
of given Iterable is True. Let’s convert the list to Iterable and check if each entry of iterable is equal to first element of list using all[] i.e. Advertisements count[] returns the occurrence count of given element in the list. Let’s call the count[] function of list with firts element of list as argument. If its occurrence count is equal to the length of list, then it means all elements in
list are Same i.e. Let’s do the same thing in single line i.e. As set contains only unique elements, so convert the list to set. If set size is 1 then it means all elements in given list are same i.e. Complete example is as follows, Output:# List of string
listOfStrings = ['Hello'] * 10
Python : all[] function
check if element are same using all[]
'''
check if element are same using all[]
It will Iterate through all the elements in list and check if all elements are similar to first element or not.
'''
result = False;
if len[listOfStrings] > 0 :
result = all[elem == listOfStrings[0] for elem in listOfStrings]
if result :
print["All Elements in List are Equal"]
else:
print["All Elements in List are Not Equal"]'''
check if element are same using list.count[]
If occurence count of first element in list is equal to length of list.
Then it means all elements in List are equal
'''
result = False;
if len[listOfStrings] > 0 :
result = listOfStrings.count[listOfStrings[0]] == len[listOfStrings]result = len[listOfStrings] > 0 and all[elem == listOfStrings[0] for elem in listOfStrings]
Check if all elements are same using Set
'''
As set contains unique elements only, so if list has similar elements, then only one will stored in set.
'''
result = len[set[listOfStrings]] == 1def main[]:
# List of string
listOfStrings = ['Hello'] * 10
# Print the List
print[listOfStrings]
'''
check if element are same using all[]
It will Iterate through all the elements in list and check if all elements are similar to first element or not.
'''
result = False;
if len[listOfStrings] > 0 :
result = all[elem == listOfStrings[0] for elem in listOfStrings]
if result :
print["All Elements in List are Equal"]
else:
print["All Elements in List are Not Equal"]
'''
check if element are same using list.count[]
If occurence count of first element in list is equal to length of list.
Then it means all elements in List are equal
'''
result = False;
if len[listOfStrings] > 0 :
result = listOfStrings.count[listOfStrings[0]] == len[listOfStrings]
if result :
print["All Elements in List are Equal"]
else:
print["All Elements in List are Not Equal"]
# Do the above logic in single line
result = len[listOfStrings] > 0 and all[elem == listOfStrings[0] for elem in listOfStrings]
if result :
print["All Elements in List are Equal"]
else:
print["All Elements in List are Not Equal"]
'''
As set contains unique elements only, so if list has similar elements, then only one will stored in set.
'''
result = len[set[listOfStrings]] == 1
if result :
print["All Elements in List are Equal"]
else:
print["All Elements in List are Not Equal"]
if __name__ == '__main__':
main[]
['Hello', 'Hello', 'Hello', 'Hello', 'Hello', 'Hello', 'Hello', 'Hello', 'Hello', 'Hello']
All Elements in List are Equal
All Elements in List are Equal
All Elements in List are Equal
All Elements in List are Equal